Bayesian simulation is increasingly exploited in the social sciences for estimation and inference of model parameters. But an especially useful (if often overlooked) feature of Bayesian simulation is that it can be used to estimate any function of model parameters, including “auxiliary” quantities such as goodness-of-fit statistics, predicted values, and residuals. Bayesian simulation treats these quantities as if they were missing data, sampling from their implied posterior densities. Exploiting this principle also lets researchers estimate models via Bayesian simulation where maximum-likelihood estimation would be intractable. Bayesian simulation thus provides a unified solution for quantitative social science. I elaborate these ideas in a variety of contexts: these include generalized linear models for binary responses using data on bill cosponsorship recently reanalyzed in Political Analysis, item—response models for the measurement of respondent's levels of political information in public opinion surveys, the estimation and analysis of legislators' ideal points from roll-call data, and outlier-resistant regression estimates of incumbency advantage in U.S. Congressional elections

Publication of King's A Solution to the Ecological Inference Problem has rekindled interest in the estimation of unknown cell values in two- and three-dimensional matrices from knowledge of the marginal sums. This paper outlines an entropy-maximizing (EM) procedure which employs more constraints than King's EI method and produces mathematical rather than statistical procedures: the estimates are maximum-likelihood values. The mathematics are outlined, and the procedure's use illustrated with a study of ticket-splitting at New Zealand's first (1996) general election using the mixed-member proportional representation system, for which official figures provide a check against the EM estimate of the number voting a straight party ticket in each constituency.

While it is very common for Congressional researchers to use interest group ratings as measures of legislator policy preferences, this paper argues that the manner in which such ratings are calculated implies that they may poorly approximate the underlying legislator preferences on which they are based. In light of this, the paper develops a technique designed to adjust interest group ratings so that they more closely correlate with legislator preferences. It argues based on Monte Carlo simulations that the technique produces adjusted ratings that improve on unadjusted ratings, and it applies the adjustment technique to historical ratings published by the Americans for Democratic Action.

As applications of duration analysis have burgeoned in political science, scholars have become increasingly aware of the potential substantive importance of duration dependence: the extent to which the conditional hazards of the events of interest are rising or falling over time. Here I discuss the issue of duration dependence, focusing on the distinction between “spurious” dependence due to unobserved heterogeneity and “true” duration dependence due to state dependence in the process of interest. I present a simple extension of a commonly used parametric duration model—the Weibull model—which allows researchers to assess the influence of causal variables on the nature and extent of duration dependence in their data. I then illustrate the application of this “generalized Weibull” model using data on the duration of international alliances.

A ranking exists in electoral systems research of different electoral formulas—the mathematical functions governing the conversion of votes into legislative seats—in terms of both proportionality of seats and votes and favorability to the largest party. I reexamine this issue with new methods and new evidence, attempting to cross-validate previous rankings using a larger and more controlled data set and more precise parametric methods than have been applied previously. The results by and large confirm previous knowledge but also illuminate several important new facets obscured in previous investigations. For example, at common ranges of district magnitude (from 5 to 15 seats), it is shown that electoral formula may matter at least as much as district magnitude in shaping proportionality.

Though the overreporting of voter turnout in the National Election Study (NES) is widely known, this article shows that the problem has become increasingly severe. The gap between NES and official estimates of presidential election turnout has more than doubled in a nearly linear fashion, from 11 points in 1952 to 24 points in 1996. This occurred because official voter turnout fell steadily from 1960 onward, while NES turnout did not. In contrast, the bias in House election turnout is always smaller and has increased only marginally. Using simple bivariate statistics, I find that worsening presidential turnout estimates are the result mostly of declining response rates rather than instrumentation, question wording changes, or other factors. As more peripheral voters have eluded interviewers in recent years, the sample became more saturated with self-reported voters, thus inflating reported turnout.

This note extends Melissa P. Collie's “Universalism and the Parties in the U.S. House of Representatives, 1921–80,” American Journal of Political Science 32, 4 (November 1988): 865–883. Detecting a strongly negative correlation between the time series of universalism and partisanship in roll call votes for the 67th through 96th U.S. Houses, Collie concluded that consensus and partisanship are alternative, rival means of organizing legislative activity. If robust, this finding ought not to be time- or chamber-specific: it should be in evidence over the whole (partisan) histories of both House and Senate, session by session. Moreover, the inverse relationship should persist under alternative operationalizations of both partisanship and universalism. Using several measures of partisanship and universalism, mostly based on roll call votes tabulated for sessions of Congress, we reassess this relationship for the 43rd through 105th Congresses. Collie's core finding persists for both chambers over the longer time span provided that one uses her measures. But results are weaker when sessions of Congress rather than Congresses are used as units of observation, and alternative operationalizations of partisanship and universalism do not strongly replicate the original finding.