Green and Shachar: Habit formation and political behaviour

Green and Shachar. 2000. Habit formation and political behaviour: Evidence of consuetude in voter turnout. British Journal of Political Science 30: 561-573.

Main Argument

Voting in one election makes you more likely to vote in future elections; voting appears to be habit-forming. Even after controlling for everything else, voting breeds more voting and abstention breeds more abstention. See Gerber, Green, and Shachar (2003) for an updated--and much more persuasive--version of this argument.

Terms

"Consuetude" is simply a pretentious word for "habit."

Methodology

The Methodological Challenge

Previous studies have controlled for as many variables as they knew to, but still found that controlling for whether a subject voted in the previous elections correlates with whether they voted in the recent elections. Thus, these previous studies have concluded that voting is habit-forming.

The problem, of course, is that these models might simply be underspecified. And if they are, then the "habit" variable is simply picking up other phenomena that went into both the previous and the current voting decision.

The Authors' Methodology

The authors attempt to get around this problem by using time series panel data (ANES) from 1972-1974 in an instrumental regression. First, they use 1972 controls to predict 1972 turnout. Then, they use 1974 controls to predict 1974 turnout. Then, they use all these variables as instruments in a final regression, which uses 1976 controls to predict 1976 turnout. Despite concluding a whole bunch of controls, they still find that previous turnout correlates with future turnout.

"Experimental" Design

The authors also use an "experimental" design, though the experiment doesn't manipulate the variable of interest (voting in a previous election). Instead, the experiment manipulates a variable known to correlate with turnout: Whether you were contacted by pollsters in the weeks before the election. They are using data from an experiment conducted in the 1970s to determine whether contact from a pollster boosts turnout (it does), but they are taking the analysis further: They use this "treatment" as an instrument to control for prior turnout, then conclude that prior turnout nonetheless correlates with current turnout.

Theoretical explanations

Recognizing that their data may not be persuasive, they nonetheless evaluate four possible explanations for these findings. They like the third.

1. Parties and candidates send more mail to people who voted last time than to nonvoters. Problem: This may be true, but the empirics control for how frequently you have been contacted by various groups, so this should be controlled for.
2. Participation boosts political efficacy (see Finkel 1985). This may be true, but the ANES controls for feelings of political efficacy.
3. The ANES does not control for "conative attitudes," a pretentious term that basically means self-confidence in the physical voting process. If you've never voted, you might not know how to register, or request an absentee ballot, or you might be afraid of being embarrassed by your inexperience when you arrive at the polls. But prior experience voting makes you less worried about these things. Thus, these "conative attitudes" might explain "consuetude."
4. Voting reinforces an identity as a good, civic person. As this identity is constructed, you continue to vote. Thus, both voting and abstention influence your self-view, thereby influencing future turnout.

Comments and Criticism

The authors suffer from the same methodological challenge as earlier studies did. Though they may have reduced the problem, it is still perfectly possible that some uncontrolled variable is being picked up in the 1972 and 1974 turnout variables, which therefore correlate with 1976 turnout. In fact, their theoretical discussion (below) suggests this very interpretation. Moreover, the later article by Gerber, Green, and Shachar all but concedes this criticism; p 541.