How to vote,whether to vote: Strategies for voting and abstaining on congressional roll calls

This paper develops and tests a theory of voting and abstaining on Congressional roll calls. The theoretical model assumes that the voting behavior of legislators is oriented toward reelection, and that constituents vote retrospectively. Among the predictions of the theory are that supporters of a program are more likely to abstain than opponents, that conflicted legislators are more likely to vote on the losing side (but will abstain when the vote is very close), and that indifferent legislators will abstain when votes are not close but trade their votes when the outcome is uncertain. The empirical test is based on a series of votes on appropriations for the Clinch River Breeder Reactor from 1975 to 1982. We estimate a nested logit model of, first, the probability of voting for Clinch River, and second, the probability of abstaining from the vote, conditional on preferences regarding the program. All of the empirical results are consistent with the theoretical predictions, and most are statistically significant by conventional standards. The implication is that the abstention decision, as well as yes or no votes, can be purposive, and that the pattern of abstentions is not random among supporters and opponents.The authors gratefully acknowledge research support from the Brookings Institution and the University of Michigan School of Law, and useful comments on an earlier draft by Randall Calvert, Morris Fiorina, Rodney Fort, Amihai Glazer, Keith Krehbiel, Thomas Romer, Kenneth Shepsle, Rodney Smith, Barry Weingast, the UCI Public Choice Study Group, and the Hoover Workshop on Collective Choice.