T he idea that observed contemporary behaviors are strongly linked to expectations about future outcomes has become so central for economists that much of economic theory has been rewritten to take explicit account of this concept (Begg 1982; Hudson 1982, chap. 3). Political scientists have also shown a growing interest in expectations, with future prospects proving to be particularly useful in studying certain aspects of electoral behavior. The now-common use of the notions of viability and electability, as well as the classification of voters as straightforward, sincere, or strategic, exemplify this trend (Abramson et al. 1992;Bartels 1988;Niemi, Whitten, and Franklin 1992). The simple act of voting is increasingly conceived of in terms of utilities (voters' preferences) and probabilities (voters' assessments of candidates' chances of winning).Two crucial questions are at the nexus of the votes-expectations literature: How do people form their expectations and What are the links between expectations and votes? We address these questions with data collected by the Gallup organization. This unique data set includes not only the usual measurement of voters' preferences among parties but also a systematic tracking of voters' expectations about the outcome of the next general election.1 The fact that this information is available on a monthly basis for more than a decade permits systematic study of the expectations formation process and of the links between expectations and votes not only during election periods but also in less intense, interelection times.2 The data are thus attractive despite their obvious limitations. 3 We shall present a simultaneous-equation votesexpectations model, 4 paying particular attention to the expectations formation process. 5 We then present our findings, which show a modest effect of expectations on voting behavior and stronger and more variegated effects-including "instantaneous" adjustments-of voting intentions on expectations. We discuss the theoretical implications of our findings in the conclusion.
A VOTES-EXPECTATIONS MODELThe votes-expectations literature has been mainly concerned with the existence and form of a pattern of reciprocal causation between voters' preferences and their assessments of the electoral campaigns (i.e., the parties' standings). Consistent with this perspective, we examine here two possibilities: (1) that voting intentions are affected by expectations about the likely winner of the next general election (bandwagon effect) and (2) that expectations about which party will win the next election are dependent on current vote intentions (whether through a sophisticated treatment of information or a simple projection effect).Practically speaking, what is required is that we devise and estimate a simultaneous equations system formed of a vote equation and an expectations equation. As is standard in simultaneous equations models, we estimate our model using two-stage least squares. To obtain consistent estimates, we must pay particular attention to model ...