Using Roll Call Estimates to Test Models of Politics

Abstract

Measuring the preferences of political elites is critically important for analyzing the determinants and consequences of elite behavior. The decisions that elites make when casting roll call votes seem to provide an ideal opportunity for measuring elite preferences and testing theories of the political process. The fact that the resulting ideal points are a consequence of applying a statistical model to a model of individual choice, however, may affect their usefulness for measuring elite preferences and testing predictions regarding individual and collective decision making. When analyzing roll call votes, scholars should be mindful of how their decisions may affect the estimates from their analyses. I use simulations to illustrate how the nonrandom selection of roll calls may affect the ability to estimate ideal points that accurately reflect the preferences responsible for generating the observed votes, and I discuss work integrating the many models involved in the production and consumption of roll call estimates.

A House Divided? Roll Calls, Polarization, and Policy Differences in the U.S. House, 1877–2011

“…While statistical identification is often achieved by imposing constraints on the ideal point parameters—assuming that legislator i ’s ideal point varies parametrically over time (e.g., constant, linear, polynomial)—it is unclear whether they can be sensibly interpreted as reflecting ideological content over time, as is commonly assumed . Some have explored how the vote‐related estimates vary over time (e.g., Clinton ), but the studies are limited by issue specificity and temporal reach . While it is common to assume that the statistical identification of roll‐call parameters over time also guarantees that it is sensible to give the estimates a consistent ideological interpretation, the sensibility of this assumed interpretation is unknown.…”

Leadership Power in Congress, 1890-2014: Evidence from PAC Contributions and Newspaper Coverage

“…are willing to transfer power to leaders when they have similar preferences to their co-partisans in the chamber and dissimilar preferences to legislators from the other party. Many roll call votes are likely subject to party pressures (e.g., Clinton, 2012;Snyder and Groseclose, 2000), which suggests that roll call based measures of preferences could be endogenous to the level of party influence. 27 Unfortunately, few obvious measures of member ideology exist that are independent of party pressures.…”

“…5 "Analyzing roll calls can only recover the preferences that rationalize the observed votes given the assumed model of individual choice as implemented via a statistical model" (Clinton, 2012). 6 Taylor (2003) is an important exception to the literature's focus on outcomes based on legislators' roll call voting behavior, but is limited to a specific time period and certain industries.…”

Strategic Behaviour in Parliament

“…Sophisticated methods to estimate ideal-points on the basis of roll call data have been developed extensively (for reviews, see Carroll & Poole, 2014;Clinton, 2012b;McCarty, 2011;Poole, 2005). Similarly, work on the effect of parties and accountability (see, for instance, Carey, 2009;Cox & McCubbins, 2005;Kam, 2001Kam, , 2008Sieberer, 2006) makes innovative use of the roll call vote record.…”