Aldrich-McKelvey scaling is a powerful method that corrects for differentialitem functioning (DIF) in estimating the positions of political stimuli (e.g., parties and candidates) and survey respondents along a latent policy dimension from issue scale data. DIF arises when respondents interpret issue scales (like the standard liberal-conservative scale) differently and distort their placements of the stimuli and themselves. We develop a Bayesian implementation of the classical maximum likelihood Aldrich-McKelvey scaling method that overcomes some important shortcomings in the classical procedure. We then apply this method to study citizens' ideological preferences and perceptions using data from the 2004-2012 American National Election Studies and the 2010 Cooperative Congressional Election Study. Our findings indicate that DIF biases self-placements on the liberal-conservative scale in a way that understates the extent of polarization in the contemporary American electorate and that citizens have remarkably accurate perceptions of the ideological positions of Senators and Senate candidates.

Political elites of the United States are deeply polarized. Polarization of the Democratic and Republican Parties is higher than at any time since the end of the Civil War. This essay describes how the modern polarization trend emerged and its implications for mass political behavior and public policy outcomes. We contend that contemporary political polarization must be understood in terms of both the ideological divergence of the parties and the expansion of the liberal-conservative dimension of conflict to a wider set of social and cultural conflicts in American society. We close with the speculation that the Republican Party has become the more fractured of the parties along the liberal-conservative dimension at both the elite and mass level.Even the most casual observer of American politics cannot help but notice that partisan conflict has grown sharper, unrelenting, and more ideological over recent decades. Pundits and ordinary citizens alike wistfully recall a bygone (though not that distant) era when DC politicians from opposite sides of the aisle could come together to have a drink, share a joke, and even occasionally pass major pieces of legislation. 1 Contemporary American politics seems to be not only more fiercely contested, but also fought over a wider range of issues-from traditional battles over the size and scope of government intervention in the economy to social/cultural battles over abortion, contraception, gay marriage, religious liberty, immigration, and gun control. These ideological divides also seem to align more closely with partisan divisions as the ranks of conservative

No abstract

Aldrich-McKelvey scaling is a powerful method that corrects for differentialitem functioning (DIF) in estimating the positions of political stimuli (e.g., parties and candidates) and survey respondents along a latent policy dimension from issue scale data. DIF arises when respondents interpret issue scales (like the standard liberal-conservative scale) differently and distort their placements of the stimuli and themselves. We develop a Bayesian implementation of the classical maximum likelihood Aldrich-McKelvey scaling method that overcomes some important shortcomings in the classical procedure. We then apply this method to study citizens' ideological preferences and perceptions using data from the 2004-2012 American National Election Studies and the 2010 Cooperative Congressional Election Study. Our findings indicate that DIF biases self-placements on the liberal-conservative scale in a way that understates the extent of polarization in the contemporary American electorate and that citizens have remarkably accurate perceptions of the ideological positions of Senators and Senate candidates. Acknowledgements: An earlier version of this paper was presented at the 2014 Annual Meeting of the Southern Political Science Association. We thank Jidong Chen for his valuable feedback. We would also like to thank the editor and the anonymous reviewers who offered helpful comments and suggestions during the review process. Data for replication, R code, and BUGS/JAGS scripts are available at: http://www.voteview.com/BAM.asp. All replication materials are also available on the AJPS Data Archive on Dataverse (http: //dvn.iq.harvard.edu/dvn/dv/ajps).

Objective. In this research note, we examine the role scientific knowledge and gender plays in citizen responses to governmental social distancing recommendations. Methods. Using two waves of the American Trends Panel Survey and a measure of latent scientific knowledge, we test whether scientific knowledge is associated with comfort in participating in social activities during the COVID-19 pandemic within both the full U.S. population and the two major political parties. Results. In both the general population and within the Democratic Party, we find that women are generally more likely to use their scientific knowledge to inform their level of comfort with social activities during the COVID-19 pandemic. Conclusion. These findings shed light on how knowledge and gender intersect to drive compliance with government recommendations and policies during a public health crisis in a deeply partisan America.