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Below results based on the criteria 'Benford'
Total number of records returned: 906

The Etiology of Public Support for the Designated Hitter Rule
Zorn, Christopher
Gill, Jeff

Uploaded 03-21-2004
Keywords baseball
designated hitter
public opinion
selection model
Abstract Since its introduction in 1973, major league baseball’s designated hitter (DH) rule has been the subject of continuing controversy. Here, we investigate the political and socio–demographic determinants of public opinion towards baseball’s DH rule, using data from a nationwide poll conducted during September, 1997. Our findings suggest that, while both self–proclaimed Democrats and Republicans are more likely to follow baseball than are political independents, it is Democrats, not Republicans, who tend to favor the DH. In addition, older respondents were more likely to oppose the rule, while respondents from the Midwest tended to favor it.

The Varying Role of Voter Information across Democratic Societies
Sekhon, Jasjeet

Uploaded 07-26-2004
Keywords Voter Information
Causal Inference
Propensity Score Matching
Robust Estimation
Survey Data
Abstract Using new robust matching methods for making causal inferences from survey data, I demonstrate that there are profound differences between how voters behave in mature democracies versus how they behave in new ones. The problems of voter ignorance and inattentiveness are not as serious in mature democracies as many analysts have suggested but are of grave concern in new democracies. Citizens in mature democracies are able to accomplish something that citizens in fledgling democracies are not: inattentive and poorly informed citizens are able to vote like their better informed compatriots and hence need to pay little attention to political events such as election campaigns in order to vote as if they were attentive. The results from the U.S. (which rely on various National Election Studies) and Mexico (2000 Panel Study) are reported in detail. Results from other countries are briefly reported.

Space Is more than Geography
Beck, Nathaniel
Gleditsch, Kristian

Uploaded 07-11-2003
Keywords spatial econometrics
time-series--cross-section data
Abstract Most spatial models use some measure of distance in the spatial weighting matrix. But this is not required: any measure of "similarity" that has the mathematical properties of distance will work well. Here we use spatial methods to allow for dyads which share a common partner to be similar (and a directed dyad and its reverse to be especially similar). While we find evidence of spatial effects in a model with a spatially lagged error, we note that the substantive conseequences of taking this into account are not great. We then use various measures of "community" to assess the impact of similarity in models of democracy and development; the three similarity measures are physical distance, cultural (religious) similarity and trade. In a simple cross-sectional model the spatial lag has large consequences; however, when we move to time-series--cross-section data the impact of the spatial lag is very small. We also argue that one can simplify estimation in many time-series--cross-sectional data sets with temporally independent errors by using the first temporal lag of the spatial lag, which makes for simple estimation.

Is Abortion A Wedge Issue for Latino Voters?
Abrajano, Marisa A.
Nagler, Jonathan
Alvarez, R. Michael

Uploaded 09-02-2002
Keywords elections
Abstract In 2000 both major parties courted the growing Latino vote. Republicans hoped to benefit among this group based on the party's pro-life position and the belief that Latinos tend to be ideologically conservative, and that Latinos, in general, are Catholic. We present evidence indicating that this strategy of appealing to Latinos based on George Bush's pro-life stance garnered him fewer votes from the Latino electorate than Republican strategists hoped. While our results confirm that abortion is influential on vote choice at the individual level, abortion's impact at the aggregate level is smaller. When we say abortion is influential at the individual level, we mean that an individual voter is affected by the candidate's position on abortion. The `effect' of abortion we talk about in this case is the change in the probability of a voter choosing Bush (or Gore) if the voter were to change his or her position on abortion while the candidates' positions on abortion remained fixed. However, at the aggregate level we are looking at what would happen if one or the other of the candidates changed his position on abortion. A change in Bush's position would affect all voters. However, abortion's relatively small aggregate level of influence when compared to its impact at the individual level is due to the fact that such a change of position by a candidate would cause him to win some Latino votes based on his abortion stance, and at the same time it would also cause him to lose Latino votes from those who have the opposite view of abortion. As such, when these Latino votes are aggregated, the overall impact of abortion on the total vote is minimal, because the two effects tend to cancel each other out. Our findings are the first we are aware of to measure this overall impact of abortion, though several previous studies (Abramowitz 1995, Alvarez and Nagler 1995 and 1998) have demonstrated the importance of abortion at the individual level. We expect our findings to be applicable to the entire electorate, not just Latinos.

Tactical Coalition Voting
Morton, Becky
McCuen, Brian

Uploaded 07-12-2002
Keywords strategic voting
proportional representation
coalition bargaining
Abstract Most research on voting in proportional representation electoral systems assumes that voters either choose sincerely for their most preferred parties or strategically if threshold constraints mean their party has little chance of winning a seat. Voters are assumed to ignore possible coalition implications of their choices. However, formal models of coalition formation in PR systems, such as Austen-Smith and Banks (1988), assume voters care about the ultimate coalition formation in the parliament and vote strategically in order to affect that coalition formation process, which we call "tactical coalition voting." In this paper, we experimentally evaluate the extent voters in a PR system engage in tactical coalition voting. We find significant evidence that voters, even those non experienced with PR systems, do choose strategically to affect post election coalitions.

Heterogeneity in Discrete Choice Models
Glasgow, Garrett

Uploaded 12-12-2001
Keywords heterogeneity
discrete choice
Abstract Nearly all empirical studies of individual behavior in political science have sought to estimate the mean relationship between some variables of interest. While such studies are vital for determining aggregate relationships between variables of interest, they are an incomplete picture of individual behavior. In particular, we generally do not pay attention to the possibility of heterogeneity, or individual-level variation in the relationships we estimate. Ignoring heterogeneity in our models means we are ignoring valuable information about individual behavior. This paper demonstrates that examining heterogeneity in discrete choice models is both important substantively and feasible methodologically. Possible sources of heterogeneity are discussed, and it is shown that these sources of heterogeneity are observationally equivalent in most cases, meaning it is generally not possible to determine the source of heterogeneity in our empirical models. Several empirical models for examining heterogeneity are described. An empirical example studying heterogeneity in union voting in the 1992 US presidential election demonstrates the

Fission and Fusion in a Party System
Benoit, Kenneth
Laver, Michael

Uploaded 07-12-2001
Keywords party systems
dynamic models
power indexes
Abstract Existing work on party systems typically involves essentially static models and pays little attention to the dynamics of party splits and fusions. Our approach explores these dynamics by setting out a simple model of legislative behavior in a parliament responsible for making and breaking governments. This model abandons the unitary actor assumption about political parties models individual legislators as utility-maximizing agents tempted to defect to other parties if this would increase their expected payoffs. We first set out a dynamic model of party fission and fusion couched in these terms and discuss this analytically. We then explore unanswered questions computationally by generating a novel type of "metadata" set, comprising the entire universe of possible legislative party systems in parliaments with up to 10 parties, generating a total of 6,292,018 theoretically possible non-equivalent legislatures. Using this metadata set and building on analytic results, we set out to characterize what makes certain parties "attractive" to legislators from other parties in a dynamic system. The results reveal an inherent instability in party systems and identify legislative configurations more prone to fission and fusion. They also strikingly highlight the role of the largest party, regardless of it size, as being attractive to potential defectors from other parties. Finally, they highlight the relatively weak position of the second-largest party. This provides an intriguing new interpretation of the potential for intense competition between the largest two parties for the role of the largest party, in a generalization to multiparty systems of the "all or nothing" competition endemic in two-party systems.

Racial and Ethnic Heterogeneity and Competition in House
Branton, Regina P.
Jones, Bradford S.

Uploaded 04-13-2001
Keywords House elections
race and politics
Abstract The principal focus of this paper is to examine how a U.S. House district's level of racial and ethnic heterogeneity is related to various indicators of electoral competition. Prior research examining the relationship between race and electoral competition has tended to focus on how a district's African American population is related to electoral outcomes. As much of this literature has focused on the important issue of racial redistricting, the primary interest in the distribution of the African American population has been reasonable (and appropriate given the research questions asked). The focus here is not directly on matters pertaining to redistricting and as such, we argue that the exclusive focus on black-white competition belies the fact that the United States is a considerably diverse country, in terms of the distribution of racial and ethnic minority groups. To understand how racial and ethnic heterogeneity impacts electoral competition in the House, we collected data on the distribution of whites, African Americans, Latinos, Asians, and Native Americans residing in U.S. House districts (using U.S. Census Bureau data). We then use an indicator measuring the degree of racial and ethnic fractionalization in district. This measure is used as a covariate in various models of incumbent electoral success. The data we use are longitudinal data on incumbent electoral success during the period 1972 to 1998. We estimate several models of electoral competition and find that racial and ethnic heterogeneity is associated with greater electoral volatility in primary elections and less volatility in general elections. Because minority group preferences tend toward the Democratic party, these relationships are more pronounced for Democrats than for Republicans. The implications of the differences in the kinds of districts Democrats represent compared to the kinds of districts Republicans represent are then discussed.

Forecasting Conflict in the Balkans using Hidden Markov Models
Schrodt, Philip A.

Uploaded 08-24-2000
Keywords forecasting
event data
hidden Markov models
Abstract This study uses hidden Markov models (HMM) to forecast conflict in the former Yugoslavia for the period January 1991 through January 1999. The political and military events reported in the lead sentences of Reuters news service stories were coded into the World Events Interaction Survey (WEIS) event data scheme. The forecasting scheme involved randomly selecting eight 100-event "templates" taken at a 1-, 3- or 6-month forecasting lag for high-conflict and low-conflict weeks. A separate HMM is developed for the high-conflict-week sequences and the low-conflict-week sequences. Forecasting is done by determining whether a sequence of observed events fit the high-conflict or low-conflict model with higher probability. Models were selected to maximize the difference between correct and incorrect predictions, evaluated by week. Three weighting schemes were used: unweighted (U), penalize false positives (P) and penalize false negatives (N). There is a relatively high level of convergence in the estimates‹the best and worst models of a given type vary in accuracy by only about 15% to 20%. In full-sample tests, the U and P models produce at overall accuracy of around 80%. However, these models correctly forecast only about 25% of the high-conflict weeks, although about 60% of the cases where a high-conflict week has been forecast turn out to have high conflict. In contrast, the N model has an overall accuracy of only about 50% in full-sample tests, but it correctly forecasts high-conflict weeks with 85% accuracy in the 3- and 6-month horizon and 92% accuracy in the 1-month horizon. However, this is achieved by excessive predictions of high-conflict weeks: only about 30% of the cases where a high-conflict week has been forecast are high-conflict. Models that use templates from only the previous year usually do about as well as models based on the entire sample. The models are remarkably insensitive to the length of the forecasting horizon‹the drop-off in accuracy at longer forecasting horizons is very small, typically around 2%-4%. There is also no clear difference in the estimated coefficients for the 1-month and 6-month models. An extensive analysis was done of the coefficient estimates in the full-sample model to determine what the model was "looking at" in order to make predictions. While a number of statistically significant differences exist between the high and low conflict models, these do not fall into any neat patterns. This is probably due to a combination of the large number of parameters being estimated, the multiple local maxima in the estimation surface, and the complications introduced by the presence of a number of very low probability event categories. Some experiments with simplified models indicate that it is possible to use models with substantially fewer parameters without markedly decreasing the accuracy of the predictions; in fact predictions of the high conflict periods actually increase in accuracy quite substantially.

Representative Bureaucracy and Harder Questions: A Response to Meier, Wrinkle, and Polinard
Nielsen, Laura B.
Wolf, Patrick J.

Uploaded 07-10-2000
Keywords representative bureaucracy
education policy
model specification
organizaional outputs
Abstract In a recently published article, Meier, Wrinkle, and Polinard (1999) reach the tantalizing conclusion that increases in the representation of minority teachers in the public school bureaucracy actually enhance the academic achievement of both minority and Anglo groups of students. However, diagnostic and statistical tests on their data suggest that their analysis may suffer from specification, selection, and categorization limitations. When corrections for these problems are introduced into the analysis, the results that are the basis for the Meier, Wrinkle and Polinard conclusions change significantly, thereby undermining our confidence in the validity of

Post-stratification without population level information on the post-stratifying variable, with application to political polling
Gelman, Andrew
Katz, Jonathan
Riley, Cavan

Uploaded 02-10-2000
Keywords Bayesian Inference
Sample surveys
State-space models
Abstract We investigate the construction of more precise estimates of a collection of population means using information about a related variable in the context of repeated sample surveys. The method is illustrated using poll results concerning presidential approval rating (our related variable is political party identification). We use post-stratification to construct these improved estimates, but since we don't have population level information on the post-stratifying variable, we construct a model for the manner in which the post-stratifier develops over time. In this manner, we obtain more precise estimates without making possibly untenable assumptions about the dynamics of our variable of interest, the presidential approval rating.

Signals, Models, and Congressional Overrides of the Supreme Court
Zorn, Christopher
Hettinger, Virginia

Uploaded 04-05-1999
Keywords event history models
split-population duration models
Supreme Court
statutory decisions
Abstract Sparked by interest in game-theoretic representations of the separation of powers, empirical work examining congressional overrides of Supreme Court statutory decisions has burgeoned in recent years. Much of this work has been hampered, however, by the relative rarity of such events; as has long been noted, congressional attention to the Court is limited, and most Court decisions represent the last word on statutory interpretation. With this fact foremost in our minds, we examine empirically a number of theories regarding such reversals. We apply a split-population duration model to the survival of Supreme Court statutory interpretation decisions. This approach allows us to separate the factors which lead to the event itself (i.e., the presence or absence of an override in a particular case) from those which influence the timing of the event. We find that case-specific factors relating to the salience of a case are an important influence in the incidence of overrides, while Congress- and Court-specific political influences dominate the timing at which those overrides occur. By separating the incidence and timing of overrides, our results yield a more accurate and nuanced understanding of this aspect of the separation of powers system.

Fractional Integration Methods in Political Science
Box-Steffensmeier, Janet M.

Uploaded 05-02-1999
Keywords Fractional integration
fractional cointegration
congressional approval
Abstract Controversies in researching political time series often revolve around the best characterization of the series, i.e., whether a series is stationary or integrated. By using a fractional integration approach, one can avoid this controversy. Fractionally integrated series are mean-reverting, but decay at different rates than a stationary series. Theoretical reasons may also lead one to expect a fractionally integrated series. Estimation of the d parameter in an ARFIMA (p, d, q) model is no longer difficult and multivariate extensions are proving useful. Using fractionally integrated methods can lead to substantive and methodological insights about political processes. We estimate d for congressional approval and economic expectations data from Durr, Gilmour, and Wolbrecht (1997) and test for fractional cointegration.

Ecological inference reversed: Estimating aggregate features of voter ideal-point distributions from individual-level data
Lewis, Jeffrey B.

Uploaded 07-13-1999
Keywords none submitted
Abstract In the last decade a great deal of progress has been made in estimating spatial models of legislative roll-call voting. There are now several well-known and effective methods of estimating the ideal points of legislators from their roll-call votes. Similar progress has not been made in the empirical modeling of the distribution of preferences in the electorate. Progress has been slower, not because the question is less important, but because of limitations of data and a lack of tractable methods. In this paper, I describe the existing technologies for inferring ideal points. I then develop a method for recovering the relative means and variances of the voter ideal point distribution across two (or more) groups of voters from individual-level binary response data. I extend the model to multiple dimensions and describe tests for dimensionality and inter-group differences. I then present Monte Carlo results demonstrating the efficacy of the meth

Estimation Of Electoral Disproportionality And Thresholds Via MCMC
Kalandrakis, Anastassios

Uploaded 11-03-1999
Keywords Electoral Disproportionality
Electoral Thresholds
Gibbs Sampling
Metropolis Algorithm
Abstract For statistical as well as political reasons -- some already identified in the literature -- measures of both electoral disproportionality and electoral thresholds are essential and must be combined in numerical summaries of electoral institutions. With few exceptions, none of these quantities can be reliably inferred directly from the provisions of the electoral law, thus impairing "large scale" comparative studies. Through the use of sampling based Bayes methods I am able to simultaneously estimate these two quantities from electoral returns. I apply the proposed procedure on 45 electoral systems in use over 216 elections to the national parliaments in the 15 countries of the European Union in the period 1945-1996. The resultant two-dimensional summary of electoral systems has several attractive properties in comparison to indices of disproportionality currently used in comparative politics.

Operationalizing and Testing Spatial Theories of Voting
Quinn, Kevin M.
Martin, Andrew D.

Uploaded 04-15-1998
Keywords spatial voting
factor analysis
multinomial probit
multinomial logit
Bayesian inference
model comparison
Bayes factors
Dutch politics
Danish politics
Abstract Spatial models of voting behavior provide the foundation for a substantial number of theoretical results. Nonetheless, empirical work involving the spatial model faces a number of potential difficulties. First, measures of the latent voter and candidate issue positions must be obtained. Second, evaluating the fit of competing statistical models of voter choice is often more complicated than previously realized. In this paper, we discuss precisely these issues. We argue that confirmatory factor analysis applied to mass-level issue preference questions is an attractive means of measuring voter ideal points. We also show how party issue positions can be recovered using a variation of this strategy. We go on to discuss the problems of assessing the fit of competing statistical models (multinomial logit vs. multinomial probit) and competing explanations (those based on spatial theory vs. those derived from other theories of voting such as sociological theories). We demonstrate how the Bayesian perspective not only provides computational advantages in the case of fitting the multinomial probit model, but also how it facilitates both types of comparison mentioned above. Results from the Netherlands and Denmark suggest that even when the computational cost of multinomial probit is disregarded, the decision whether to use multinomial probit (MNP) or multinomial logit (MNL) is not clear-cut.

Indifference, Voting, and Abstention in the 1976 Presidential Election
Herron, Michael C.

Uploaded 05-19-1998
Keywords 1976 election
Abstract This paper develops a statistical model of voting and abstention and applies it to the presidential election of 1976, a contest between incumbent president Gerald Ford and Democratic challenger Jimmy Carter. Our model is grounded in random utility theory, and, unlike many extant models of voting and abstention, its treatment of turnout focuses on the distinction between political extremists and individuals who were close to indifferent between Ford and Carter. We expect that individuals close to indifferent abstained at lower rates than political extremists. And, in light of research which highlights relatively high abstention rates among Democratic supporters, our model allows politically--left extremists to abstain at different rates than politically--right extremists. We uncover some evidence that indifference between Ford and Carter exerted a downward influence on voting propensity in 1976. However, there is much stronger evidence that individuals who were politically--left extremists abstained at higher rates than all others. We also find that individuals who anticipated a close election in 1976 voted at higher rates than those who expected a lopsided victory. The value of the paper's model is its focus on the relation between abstention and strength of preference. Generalizations and applications of the model to additional presidential elections should foster a determination of whether indifference is as important to abstention as is politically--left extremism.

A Statistical Assessment of The Spatial Model of Ideology
Ghobarah, Hazen

Uploaded 07-20-1998
Keywords spatial theory
maximum likelihood
multi-dimensional scaling
Abstract The spatial model of ideology (Hinich and Munger, 1994) specifies a formal framework for linking positions of the electorate, the parties, and the candidates on a plethora of issues to positions on a few ideological dimensions- perhaps just one or two dimensions. While extant tests of this model have relied on cross-sectional survey data, this study utilizes a panel. The panel format allows a direct examination of the stability, and indeed the reality, of the parameters and the cognitive processes that are posited by the formal model. Given the available variables in the panel, I operationalize one model for party competition and another for presidential candidates. The results of both are supportive of the linkage model. The statistical methodology used in this study is no more complex than the model requires; it includes maximum likelihood factor analysis and a customized multi-dimensional scaling procedure.

Direction and Intensity of Russian Macroeconomic Evaluations
Jones, Bradford S.
Willerton, John P.
Sobel, Michael E.

Uploaded 08-30-1998
Keywords Russia
public opinion
log linear models
Abstract The Russian macroeconomy has exhibited volatility since the transformation from the Soviet Union to the Russian Federation. Much is known about the Russian public opinion climate during the end of the Soviet era and the beginning of the Russian Federation era; however, less well understood is the nature of Russians' macroeconomic evaluations during this on-going transformation. In this paper, we analyze Russians' assessments of the macroeconomy using Russian public opinion data asking respondents to assess the Russian national economy. We establish four testable hypotheses. First, we hypothesize that the direction of Russian opinion will be asymmetrically more negative than positive across all periods in the study. Second, we hypothesize that economic assessments will vary by residential region. Specifically, we contend the response distribution for respondents from Moscow and St. Petersburg (MSP) will differ from respondents from other residential regions. Third (and related to the second), we hypothesize that the response distributions for MSP respondents will be temporally heterogenous while the response distribution for respondents outside MSP will be temporally homogenous. Fourth, we hypothesize that despite the poor performance of the economy during the Russian Federation transition, Russian public opinion will not exhibit extreme negativity in macroeconomic evaluations. Using published survey data collected from the bi -monthly extsl{Russian Public Opinion Monitor} conducted by the Russian Center for Public Opinion Research (VCIOM), for the period January 1994 to July 1996, we examine both the direction and intensity of Russian opinion toward the state of the national economy by estimating the distribution on the response variable using an adjacent category logit model (Jones and Sobel 1998, Sobel 1995, 1997, 1998). From our analysis, we find first that the direction of Russians' evaluation of the macroeconomy is consistently negative rather than positive---a finding that corroborates extant research; however, the directional nature of economic assessments displays significant residential variation between MSP and the rest of the country. Second, we find significant residential variation in economic assessments. Specifically, the response distribution for MSP respondents can be distinguished from the response distribution from respondents in other residential regions, and also, the response distribution for MSP respondents displays considerable temporal heterogeneity. We argue this variability tends to follow changes in the macroeconomic and political environments. Third, we do not find support for the hypothesis of temporal homogeneity in the response distribution for respondents outside of MSP. Nevertheless, residents in other cities and in rural regions seem not to be as responsive to macroeconomic changes over the period, thus eliciting milder temporal variability than MSP respondents. Fourth, we find that in terms of the response distribution, the intensity of Russian pessimism (or optimism) is extsl{not} extreme.

Strategic Position-Taking and the Timing of Voting Decisions in Congress
Box-Steffensmeier, Janet M.
Zorn, Christopher
Arnold, Laura W.

Uploaded 01-01-1995
Keywords timing
Congressional voting
duration models
proportional hazards
survival rate
Abstract Voting behavior is intimately linked with many of the most prominent questions of concern to students of legislatures, including the strength of legislative parties and factions, the parameters of individual decision making, and the nature of representation (Collie 1985). One critical element of voting in legislatures is the timing of various choices legislators make. The study of strategic position taking and the timing of voting decisions is important for three major reasons: it adds information about the context and sequence of decision making; the analysis more closely approximates members' strategic considerations; and finally, in contrast to most of the literature on legislative roll call voting, the process is examined rather than strictly the result. Yet, despite the importance of position taking and timing, no one has examined comprehensively this crucial aspect of timing. Research on the timing of voting decisions provides insight into theoretical questions regarding the strategic behavior of legislators, institutional constraints on member behavior, and strategies of interest group influence. The project examines the vote to ratify the North American Free Trade Agreement, which has been called ". . . the most important vote on Capital Hill since the Berlin Wall came down" (Frenzel 1994, 3).

Estimating Ideal Points in Small Legislatures...
Londregan, John

Uploaded 00-00-0000
Keywords scaling methods
legislative committees
Abstract A spatial model that incorporates both the voting decision and the proposal making process is set forth and applied to the setting of committees in the Chilean Senate, the model returns information about the spatial preferences and the proposal making abilities of legislators. Estimates for five committees in the Chilean Senate are presented, and the preferences and proposal making tendencies of Chile's appointed and elected senators are compared.

Uncertainty and Ambivalence in the Ecology of Race
Alvarez, R. Michael
Brehm, John

Uploaded 08-22-1996
Keywords racial policy
affirmative action
ecological inference
heteroskedastic ordered logit
value conflict
Abstract Since Myrdal (1944), scholars have regarded American attitudes towards racial policy as a conflict between values, groups, and interests. Although Myrdal viewed the conflict as a state internal to individuals, it begins as aggregate conflict. This mix of ecologies---individual and aggregate---carries forth to the present. This paper takes the question of different ecologies for racial politics seriously, developing tools to compare conflict at individual and aggregate level. We demonstrate that individual racial policy choices stems principally from racial resentment, and that the variability of that choice indicates a state of uncertainty, not ambivalence or equivocation. We further demonstrate that racial resentment does not surface as a predictor of aggregate racial policy choice, even though individual choices about racial policies appear to be more strongly influenced by the level of political informedness.

Do Voters Learn from Presidential Election Campaigns?
Alvarez, R. Michael
Glasgow, Garrett

Uploaded 10-27-1997
Keywords random effects panel models
content analysis
presidential election campaigns
voter decisionmaking
voter learning
Abstract We present a model of voter campaign learning which is based on Bayesian learning models. This model assumes voters are imperfectly informed and that they incorporate new information into their existing perceptions about candidate issue positions in a systematic manner. Additional information made available to voters about candidate issue positions during the course of a political campaign will lead voters to have more precise perceptions of the issue positions of the candidates involved. We use panel survey data from the 1976 and 1980 presidental elections, combined with content analyses of the media during these same elections. Our primary analysis is conducted using random effects panel models. We find that during each of these campaigns many voters became better informed about the positions of candidates on many issues and that these changes in voter information are directly related to the information flow during each presidential campaign.

Measuring Party Cohesion on Roll Call Votes with an Application to the Labor Committee of the Chilean Senate
Londregan, John B.

Uploaded 08-22-1997
Keywords Maximum Likelihood
Roll Call Voting
Abstract I introduce measures of two forms of party cohesion, affinity, in which members of the same party share a similar ideological outlook, and would vote alike in any event, and discipline, in which legislators of the same party compromise their basic ideological positions on party votes. These measures are based on maximum likelihood estimates of a spatial model of voting. Applied to the Labor Committee of the Chilean Senate the analysis identifies substantial affinity among elected Senators from the ruing Concertacion coalition, while the Institutional Senators exhibit marked differences in their ideological affinities. Neither of the discipline measures exceeds the threshold of tatistical significance.

The Political Entropy of Vote Choice: An Empirical Test of Uncertainty Reduction
Gill, Jeff

Uploaded 08-05-1997
Keywords Entropy
Voting Under Uncertainty
Proximity Spatial Voting Model
Heteroscedastic Probit
Abstract Recent literature in voting theory has developed the idea that individual voting preferences are probabilistic rather than strictly deterministic. This work builds upon spatial voting models (Enelow and Hinich 1981, Ferejohn and Fiorina 1974, Davis, DeGroot and Hinich 1972, Farquharson 1969) by introducing probabilistic uncertainty into the calculus of voting decision on an individual level. Some suggest that the voting decision can be modeled with traditional probabilistic tools of uncertainty (Coughlin 1990, Coughlin and Nitzen 1981). Entropy is a measure of uncertainty that originated in statistical thermodynamics. Essentially, entropy indicates the amount of uncertainty in probability distributions (Soofi 1992), or it can be thought of as signifying a lack of human knowledge about some random event (Denbigh and Denbigh, 1985). Entropy in statistics developed with Kolmogorov (1959), Kinchin (1957), and Shannon (1948), but has rarely been applied to social science problems. Exceptions include Darcy and Aigner's (1980) use of entropy to analyze categorical survey responses in political science, and economic applications by Theil (1967) and Theil and Fiebig (1984). I examine voters' uncertainty as they assess candidates, and measure policy positions. I then test whether or not these voters minimize the cost of voting (specifically the cost of information) by determining a maximum entropy selection. Except for the inclusion of entropy terms, this approach is similar to others in the recent literature. In this paper I develop a measure to aggregate evaluation of issue uncertainty and corresponding vote choice where the uncertainty parameterization is derived from an entropy calculation on a set of salient election issues. The primary advantage of this approach is that it requires very few assumptions about the nature of the data. Using 1994 American National Election Study survey data from the Center for Political Studies, I test the hypothesis that the ``Contract with America'' reduced voter uncertainty about the issue positions of Republican House candidates. The entropic model suggests that voters used the written and explicit Republican agenda as a means of reducing issue uncertainty without substantially increasing time spent evaluating candidate positions.

Why Study Only Presidential Campaigns? Statewide Races as a Laboratory for Campaign Analysis
Alvarez, R. Michael

Uploaded 06-19-1997
Keywords presidential campaigns
statewide campaigns
campaign dynamics
voter learning
study design
case studies
Abstract Political campaigns play a central role in democratic politics since they are an important source of contact between citizens and voters. But the literature has been quite pessimistic about whether political campaigns can influence the preferences and behavior of voters. In this paper I argue that one of the primary reasons for this pessimism stems from the consistent and lasting focus on presidential campaigns. While presidential campaigns are an important aspect of the American political process, they make poor laboratories for the study of campaigns. Instead I argue that statewide political campaigns provide a much better laboratory for the study of campaigns. The paper presents a series of empirical analyses of statewide campaigns and concludes with a discussion of different designs for the study of statewide campaigns.

Changing Minds? Not in Congress!
Poole, Keith T.

Uploaded 03-19-1997
Keywords rank orderings
ideological consistency
Abstract This paper shows a variety of evidence that members of Congress are ideologically consistent. The bulk of the evidence is from an analysis of rank-orderings of the members of the Post-World War II Congresses (80-104). A simple method of estimating rank orders that maximizes the correct classification of the observed roll call voting choices is shown in an appendix. A joint rank-ordering of all members of the House, Senate, and the 9 Presidents from Eisenhower to Clinton, accounts for 86.1 percent of the 6.9 million choices during the period. The Spearman correlation between the relative rank orderings within the two Chambers of the 123 members who served in both the House and Senate during the period was .92. Based upon the roll call voting record, once elected to Congress, members adopt a consistent ideological position and maintain it over time. There may be changing minds, but they are not in Congress.

Problems with and Solutions for Two-dimensional Models of Continuous Dependent Variables
Goodrich, Ben

Uploaded 05-24-2005
Keywords TSCS
fixed effects
random effects
between estimator
pooled OLS
Abstract This paper addresses hierarchical models with continuous dependent variables, such as time-series-cross-section models. Building on the argument in Zorn (2001), the main point of this paper is that the pooled OLS estimator is deeply flawed – especially for time-series-cross-section data – but for reasons that have not explicitly been raised in previous papers. The pooled OLS estimator, the within-estimator, the between-estimator, and the random effects estimator can be seen as special cases of the fractionally pooled estimator presented in Bartels (1996), which allows all of these estimators to be evaluated in a common framework. Taking bias and efficiency into account, using both the within-estimator and the between-estimator is likely to be the best estimation strategy for the vast majority of applications in political science.

Genetic Matching for Estimating Causal Effects: A General Multivariate Matching Method for Achieving Balance in Observational Studies
Diamond, Alexis
Sekhon, Jasjeet

Uploaded 07-19-2005
Keywords Matching
Propensity Score
Causal Inference
Genetic Algorithm
Evolutionary Programming
Program Evaluation
Abstract Genetic matching is a new method for performing multivariate matching which uses an evolutionary search algorithm to determine the weight each covariate is given. The method utilizes an evolutionary algorithm developed by Mebane and Sekhon (1998; Sekhon and Mebane 1998) that maximizes the balance of observed potential confounders across matched treated and control units. The method is nonparametric and does not depend on knowing or estimating the propensity score, but the method is greatly improved when a known or estimated propensity score is incorporated. Genetic matching reliably reduces both the bias and the mean square error of the estimated causal effect even when the property of equal percent bias reduction (EPBR) does not hold. When this property does not hold, matching methods---such as Mahalanobis distance and propensity score matching---often perform poorly. Even if the EPBR property does hold and the propensity score is correctly specified, in finite samples, estimates based on genetic matching have lower mean square error than those based on the usual matching methods. We present a reanalysis of the LaLonde (1986) job training dataset which demonstrates the benefits of genetic matching and which helps to resolve a longstanding debate between Dehejia and Wahba (1999, 2002); Dehejia (2005) and Smith and Todd (2001, 2005a,b) over the ability of matching to overcome LaLonde's critique of nonexperimental estimators. Monte Carlos are also presented to demonstrate the properties of our method.

Struggles with survey weighting and regression modeling
Gelman, Andrew

Uploaded 10-12-2005
Keywords multilevel modeling
poststrati cation
sampling weights
Abstract The general principles of Bayesian data analysis imply that models for survey responses should be constructed conditional on all variables that affect the probability of inclusion and nonresponse, which are also the variables used in survey weighting and clustering. However, such models can quickly become very complicated, with potentially thousands of post-stratification cells. It is then a challenge to develop general families of multilevel probability models that yield reasonable Bayesian inferences. We discuss in the context of several ongoing public health and social surveys. This work is currently open-ended, and we conclude with thoughts on how research could proceed to solve these problems.

Two's Company, Three's an Equilibrium: Strategic Voting and Multicandidate Elections
Patty, John

Uploaded 07-15-2006
Keywords Multicandidate elections
undominated equilibrium
spatial competition
Abstract In this paper, I characterize equilibria in multicandidate elections. Recognizing that electoral equilibrium involves both candidates’ and voters’ strategies, I first prove existence of pure strategy electoral equilibria when candidates seek to maximize their vote share. Accordingly, the main difficulty with electoral equilibria is multiplicity. I prove that, even after restricting attention to subgame perfect Nash equilibria in weakly undominated strategies, the set of electoral equilibria is very large. I provide characterizations of candidates’ equilibrium platforms, type distributions under which there exist convergent equilibria in which all candidates announce identical platforms, and platforms that can not win in equilibrium. I also examine welfare implications of the results, connections between the noncooperative equilibria, the core, and the uncovered set. Finally, I consider the implications of probability of victory maximization by the candidates.

The Future of Partisan Symmetry as a Judicial Test for Partisan Gerrymandering after LULAC v. Perry
Grofman, Bernard
King, Gary

Uploaded 08-04-2006
Keywords Gerrymandering
random effects
partisan symmetry
Abstract While the Supreme Court in Bandemer v. Davis found partisan gerrymandering to be justiciable, no challenged redistricting plan in the subsequent 20 years has been held unconstitutional on partisan grounds. Then, in Vieth v. Jubilerer, five justices concluded that some standard might be adopted in a future case, if a manageable rule could be found. When gerrymandering next came before the Court, in LULAC v. Perry, we along with our colleagues filed an Amicus Brief (King et al., 2005), proposing that a test be based in part on the partisan symmetry standard. Although the issue was not resolved, our proposal was discussed and positively evaluated in three of the opinions, including the plurality judgment, and for the first time for any proposal the Court gave a clear indication that a future legal test for partisan gerrymandering will likely include partisan symmetry. A majority of Justices now appear to endorse the view that the measurement of partisan symmetry may be used in partisan gerrymandering claims as “a helpful (though certainly not talismanic) tool” (Justice Stevens, joined by Justice Breyer), provided one recognizes that “asymmetry alone is not a reliable measure of unconstitutional partisanship” and possibly that the standard would be applied only after at least one election has been held under the redistricting plan at issue (Justice Kennedy, joined by Justices Souter and Ginsburg). We use this essay to respond to the request of Justices Souter and Ginsburg that “further attention … be devoted to the administrability of such a criterion at all levels of redistricting and its review.” Building on our previous scholarly work, our Amicus Brief, the observations of these five Justices, and a supporting consensus in the academic literature, we offer here a social science perspective on the conceptualization and measurement of partisan gerrymandering and the development of relevant legal rules based on what is effectively the Supreme Court’s open invitation to lower courts to revisit these issues in the light of LULAC v. Perry. (Forthcoming, January 2007 Election Law Journal. Comments welcome.)

Incumbency as a Source of Contamination in Mixed Electoral Systems
Hainmueller, Jens
Kern, Holger Lutz

Uploaded 03-10-2006
Keywords contamination
mixed electoral systems
causal inference
regression-discontinuity design
treatment effects
Abstract In this paper we demonstrate empirically that incumbency is a source of contamination in Germany's mixed electoral system. Using a quasi-experimental research design that allows for causal inference under a weaker set of assumptions than the regression models commonly used in the electoral systems literature, we find that incumbency causes a gain of $1.4$ to $1.7$ percentage points in PR vote shares. We also present simulations of Bundestag seat distributions to demonstrate that contamination effects caused by incumbency are sufficiently large to trigger significant shifts in parliamentary majorities

Bayesian Analysis of Structural Changes: Historical Changes in US Presidential Uses of Force Abroad
Park, Jong Hee

Uploaded 07-16-2007
Keywords structural changes
changepoint models
discrete time series data
use of force data
state space models
time-varying parameter models
Bayesian inference
Abstract While many theoretical models in political science are inspired by structural changes in politics, most empirical methods assume stable patterns of causal processes and fail to capture dynamic changes in theoretical relationships. In this paper, I introduce an efficient Bayesian approach to the multiple changepoint problem presented by Chib (1998) and discuss the utility of the Bayesian changepoint models in the context of generalized linear models. As an illustration, I revisit the debate over whether and how U.S. presidents have used forces abroad in response to domestic factors since 1890.

Two Genes Predict Voter Turnout
Fowler, James
Dawes, Christopher

Uploaded 11-26-2007
Abstract Fowler, Baker, and Dawes (2007) recently showed in two independent studies of twins that voter turnout has very high heritability. Here we investigate two specific genes that may contribute to this heritability via their impact on neurochemical processes that influence social behavior. Using data from the National Longitudinal Study of Adolescent Health, we show that a polymorphism of the MAOA gene significantly increases the likelihood of voting. We also find evidence of a gene-environment interaction between religious attendance and a polymorphism of the 5HTT gene that significantly increases voter turnout. These are the first results to ever link specific genes to political behavior and they suggest that political scientists should take seriously the claim that at least some variation in political behavior is due to innate predispositions.

Using Item Response Theory to Estimate Ideology in Congress
Kropko, Jonathan

Uploaded 06-28-2008
Keywords Item Response Theory
Abstract I use item response theory (IRT) to estimate latent ideology from selected roll-call votes in the first session of the 110th House of Representatives. Votes are selected if they are divisive, unique, but not wholly explained by party loyalties. The method is similar to the one employed by Clinton et al (2004), but does not assume a spatial structure of voting. The results demonstrate that (1) although Democrats hold a majority of the seats in the 110th House, a majority of the members have conservative ideologies, (2) the Republican party leadership is much more conservative than the Democratic party leadership is liberal, and (3) that the House is far less ideologically polarized than DW-Nominate scores would indicate.

The Strategic Interdependence of Foreign Aid: A Theoretically Informed Application of the Spatial Autoregressive Model
Steinwand, Martin

Uploaded 07-07-2008
Keywords Spatial Autoregressive Model
Connectivity Matrix
Public Goods
Abstract Spatial statistical methods in political science provide a tool to deal with spatial and other forms of interdependence in observational data. However, political scientist have been slow to use theory in conceptualizing how political units interconnect other than through geography. In this paper, I use a game theoretic impure public good model to derive the connectivity matrix for a spatial autoregressive (SAR) statistical model. I estimate two SAR models with pure respectively impure public good weights and compare their performance in summarizing data on international aid commitments from 1974 to 2006. I find some evidence for impure public good characteristics of aid during the cold war, and strong evidence for pure public good characteristics after the end of the cold war.

Giving Order to Districts: Estimating Voter Distributions with National Election Returns
Kernell, Georgia

Uploaded 07-07-2008
Keywords district ideology
voter distribution
election returns
Abstract Correctly measuring district preferences is crucial for empirical research on legislative responsiveness and voting behavior. This article argues that the common practice of using presidential vote shares to measure congressional district ideology systematically produces incorrect estimates. I propose an alternative method that employs multiple election returns to estimate voters' ideological distributions within districts. I develop two estimation procedures -- a least squared error model and a Bayesian model -- and test each with simulations and empirical applications. The models are shown to outperform vote shares, and they are validated with direct measures of voter ideology and out of sample election predictions. Beyond estimating district ideology, these models provide valuable information on constituency heterogeneity, an important but understudied quality for understanding representatives' strategic behavior.

Beyond "Fixed Versus Random Effects": A Framework for Improving Substantive and Statistical Analysis of Panel, TSCS, and Multilevel Data
Bartels, Brandon

Uploaded 09-30-2008
Keywords random effects
fixed effects
time-series cross-sectional data
panel data
multilevel modeling
Abstract Researchers analyzing panel, time-series cross-sectional, and multilevel data often choose between a random effects, fixed effects, or complete pooling modeling approach. While pros and cons exist for each approach, I contend that some core issues concerning clustered data continue to be ignored. I present a unified and simple modeling framework for analyzing clustered data that solves many of the substantive and statistical problems inherent in extant approaches. The approach: (1) solves the substantive interpretation problems associated with cluster confounding, which occurs when one assumes that within- and between-cluster effects are equal; (2) accounts for cluster-level unobserved heterogeneity via a random intercept model; (3) satisfies the controversial statistical assumption that level-1 variables be uncorrelated with the random effects term; (4) allows for the inclusion of level-2 variables; and (5) allows for statistical tests of cluster confounding. I illustrate this approach using three substantive examples: global human rights abuse, oil production for OPEC countries, and Senate voting on Supreme Court nominations. Reexaminations of these data produce refined interpretations of some of the core substantive conclusions.

Estimation in Dirichlet Random Effects Models
Kyung, Minjung
Gill, Jeff
Casella, George

Uploaded 04-28-2009
Keywords generalized linear mixed model
Dirichlet process random effects model
precision parameter likelihood
Gibbs sampling
importance sampling
probit mixed Dirichlet random effects model
Abstract We develop a new Gibbs sampler for a linear mixed model with a Dirichlet process random effect term, which is easily extended to a generalized linear mixed model with a probit link function. Our Gibbs sampler exploits the properties of the multinomial and Dirichlet distribution, and is shown to be an improvement, in terms of operator norm and efficiency, over other commonly used MCMC algorithms. We also investigate methods for the estimation of the precision parameter of the Dirichlet process, finding that maximum likelihood may not be desirable, but a posterior mode is a reasonable approach. Examples are given to show how these models perform on real data. Our results complement both the theoretical basis of the Dirichlet process nonparametric prior and the computational work that has been done to date. Forthcoming: Annals of Statistics.

Balancing Competing Demands: Position-Taking and Election Proximity in the European Parliament
Lindstaedt, Rene
Slapin, Jonathan
Vander Wielen, Ryan

Uploaded 07-31-2009
Keywords Legislative Politics
European Parliament
Comparative Politics
Bayesian IRT
Formal Theory
Abstract Parties value unity, yet, members of parliament face competing demands, giving them incentives to deviate from the party. For members of the European Parliament (MEPs), these competing demands are national party and European party group pressures. Here, we look at how MEPs respond to those competing demands. We examine ideological shifts within a single parliamentary term to assess how European Parliament (EP) election proximity affects party group cohesion. Our formal model of legislative behavior with multiple principals yields the following hypothesis: When EP elections are proximate, national party delegations shift toward national party positions, thus weakening EP party group cohesion. For our empirical test, we analyze roll call data from the fifth EP (1999-2004) using Bayesian item response models. We find significant movement among national party delegations as EP elections approach, which is consistent with our theoretical model, but surprising given the existing literature on EP elections as second-order contests.

Invaluable Involvement: Purposive Interest Group Networks in the 21st Century

Uploaded 02-04-2010
Keywords Network Analysis
Interest Groups
Amicus Curiae
Coalition Strategy
Abstract We present the first comprehensive social network analysis of purposive and coordinated interest group relationships. We utilize a network measure based on cosigner status to United States Supreme Court amicus curiae, or friend of the court briefs. The illuminated structures lend insight into the central players and overall formation of the network over the first seven years of the 21st century. We find that the majority of interest groups primarily partake in coalition strategies with other groups of similar policy interest and ideological character. This is in contrast to previous literature that focused only on one or the other. Network analysis provides evidence, for example, that the National Wildlife Foundation, the National Association of Criminal Defense Lawyers and the American Civil Liberties Union are all particularly strong groups, but exploit different central roles.

Detecting heterogeneous treatment effects in large-scale experiments using Bayesian Additive Regression Trees
Green, Donald
Kern, Holger

Uploaded 07-16-2010
Keywords causal inference
ensemble methods
tree models
Abstract We present a method that largely automates the search for systematic treatment effect heterogeneity in large-scale experiments. We introduce an estimator recently proposed in the statistical learning literature, Bayesian Additive Regression Trees (BART), to model treatment effects that vary as a function of covariates. BART has two important advantages over commonly employed parametric modeling strategies: it automates the search for treatment-covariate interactions and models them in a very flexible manner. To increase the reliability and credibility of the resulting conditional average treatment effect estimates, we suggest the use of a split sample analysis, which randomly divides the data into two equally-sized parts. The first part is used to search for systematic treatment effect heterogeneity; the second part is used to confirm the results. This approach permits a relatively unstructured exploration of systematic treatment effect heterogeneity while avoiding the pitfalls of data dredging and multiple comparisons. We illustrate the value of our approach by offering two empirical examples, a survey experiment on Americans' support for social welfare spending and a voter mobilization field experiment. In both applications, our approach provides robust insights into the nature and extent of systematic treatment effect heterogeneity.

Modeling History Dependence in Network-Behavior Coevolution
Franzese, Robert
Hays, Jude
Kachi, Aya

Uploaded 07-21-2010
Keywords path dependence
history dependence
spatial econometrics
markov chain
military alliance
conflict behavior
Abstract Spatial interdependence--the dependence of outcomes in some units on those in others--is substantively and theoretically ubiquitous and central across the social sciences. Spatial association is also omnipresent empirically. However, spatial association may arise from three importantly distinct processes: common exposure of actors to exogenous external and internal stimuli, interdependence of outcomes/behaviors across actors (contagion), and/or the putative outcomes may affect the variable along which the clustering occurs (selection). Accurate inference about any of these processes generally requires an empirical strategy that addresses all three well. From a spatial-econometric perspective, this suggests spatiotemporal empirical models with exogenous covariates (common exposure) and spatial lags (contagion), with the spatial weights being endogenous (selection). From a longitudinal network-analytic perspective, we can identify the same three processes as potential sources of network effects and network formation. From that perspective, actors' self-selection into networks (by, e.g., behavioral homophily) and actors' behavior that is contagious through those network connections likewise demands theoretical and empirical models in which networks and behavior coevolve over time. This paper begins building such modeling by, on the theoretical side, extending a Markov type-interaction model to allow endogenous tie-formation, and, on the empirical side, merging a simple spatial-lag logit model of contagious behavior with a simple p-star logit model of network formation, building this synthetic discrete-time empirical model from the theoretical base of the modified Markov type-interaction model. One interesting consequence of network-behavior coevolution--identically: endogenous patterns of spatial interdependence--emphasized here is how it can produce history-dependent political dynamics, including equilibrium phat and path dependence (Page 2006). The paper explores these implications, and then concludes with a preliminary demonstration of the strategy applied to alliance formation and conflict behavior among the great powers in the first half of the twentieth century.

The Immigration Issue and the 2010 House Elections: A Research Design
Monogan, Jamie

Uploaded 11-02-2010
Keywords causal inference
propensity score
Abstract This paper proposes a research design for evaluating the effect of Republican candidates' immigration stances on House election outcomes. It develops a measure of immigration stance which is based on the text of each candidate's issue statement. With this as the treatment, propensities to support a harsh line on immigration are calculated for each candidate based on a variety of covariates that also may influence election outcomes. In this way, a research design is developed before election outcomes are observed. Thus, this project clearly reflects the advice of Rubin, who argues that the research design ought to be set before the outcome is even observed.

A Mixed-Membership Approach to the Assessment of Political Ideology from Survey Responses
Gross, Justin
Manrique-Vallier, Daniel

Uploaded 07-13-2012
Keywords latent structure model
latent variables
core values
discrete factor analysis
survey response
Abstract We employ mixed-membership (or grade-of-membership) techniques--of growing popularity in medical diagnostics, psychology, genetics, and machine learning--in order to identify prototypical profiles of survey respondents based on their answers to questions aimed at uncovering their basic orientations or ideological predispositions. In contrast with factor analytic techniques and IRT approaches, we treat both manifest and latent variables as categorical. A mixed membership model may be thought of as a generalization of latent class modeling, in which individuals act as members of more than one class. This notion is well-aligned with earlier theoretical work of Zaller, Feldman, Stimson, and others, who at times envision respondents to be internally complex, answering survey questions probabilistically according to what Zaller calls varying ``considerations.'' Reanalyzing data in this way, we develop new insights into the sorts of constraints that may structure mass belief systems.

Using Qualitative Information to Improve Causal Inference
Glynn, Adam
Ichino, Nahomi

Uploaded 09-23-2012
Keywords case study
causal inference
mixed methods
sensitivity analysis
observational study
Abstract We demonstrate four techniques that utilize case studies to improve causal inference within the Rosenbaum [2002, 2009] approach to observational studies. This approach accommodates small to medium sample sizes in a nonparametric framework and does not require the elicitation of Bayesian priors. First, we show that this approach allows case studies to ameliorate the effects of poorly measured outcomes, sometimes reducing p-values. Second, we show that qualitative information can be incorporated in an analysis and presented as qualitative confidence intervals. Third, we demonstrate that a standard technique of comparative case studies can improve sensitivity analysis within this framework, sometimes reducing the sensitivity of p-values to unmeasured confounders. Finally, we demonstrate that qualitative information on the heterogeneity of treatments can be used to check the robustness of p-values. We illustrate these methods by examining the effect of not having a runoff provision on opposition harassment in transitional presidential elections in 1990s sub-Saharan Africa.

The fault in our stars: Measuring and correcting significance bias in Political Science
Esarey, Justin
Wu, Ahra

Uploaded 01-16-2014
Keywords significance
hypothesis test
Abstract Prior research finds that statistically significant results are overrepresented in scientific publications. If significant results are consistently favored in the review process, published results will systematically overstate the magnitude of their findings. Worse yet, the typical two-tailed statistical significance test with \alpha=0.05 does little to prevent the proliferation of false positives in the literature. In this paper, we systematically measure the impact of these two forms of significance bias on published research in quantitative political science. We estimate that 35% or more of published results exaggerate their substantive significance to a meaningful degree, with an average upward bias of 9%-20%. Additionally, 15%-35% of published results are at elevated risk of being false positives. Most importantly, we evaluate a variety of new and existing methodological strategies to correct both forms of significance bias. We conclude that a smaller \alpha threshold combined with conservative Bayesian priors is an effective remedy.

Reconsidering Tests for Ambivalence in Political Choice Survey Data
Glasgow, Garrett

Uploaded 03-21-2004
Keywords ambivalence
heteroskedastic discrete choice
Abstract The concept of ambivalence challenges the assumption that individuals combine their positive and negative attitudes towards objects in their choice set into unidimensional attitudes, instead maintaining that individuals can simultaneously hold conflicting attitudes. Unfortunately, most tests for ambivalence in political choice survey data are inconclusive. In particular, the empirical results of these tests could also be explained by a choice model with unidimensional attitudes. There are two related reasons for this. First, individuals who appear to be close to neutrality or indifference in a choice model with unidimensional attitudes are expected to have observed choice behavior identical to that expected from ambivalent individuals. Second, the measures of ambivalence developed and used in survey-based studies of ambivalence in political choice are closely related to measures of neutrality or indifference in a unidimensional attitude choice model. Taken together, these two observations point out the need to reconsider our empirical tests of ambivalence if we wish to determine if and how ambivalence influences individual political choice behavior.

Models of Intertemporal Choice
Wand, Jonathan

Uploaded 07-26-2004
Keywords choice
extremal process
utility maximizing
lagged dependent variable
Abstract In this paper, I consider the behavior of individuals making repeated choices over a finite set of discrete alternatives. Individuals are assumed to maximize utility each time they are faced with a choice, without affecting the utility or availability of future choices. I build on a class of models where serial correlation in choices is due to a process of learning over time about the merits of alternatives, rather than due to unobserved persistent effects. I provide new analytical results for characterizing transition probabilities between choices without imposing restrictions on how the systematic component of utilities may change over time.

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