Downs: An economic theory of democracy

Downs. 1957. An economic theory of democracy. New York: Harper and Row.

In Brief

Downs presents a rational calculus of voting that has inspired much of the later work on voting and turnout. Particularly significant was his conclusion that a rational voter should almost never bother to vote. This conclusion, especially as elaborated on by Riker and Ordeshook (1968) has shifted the attention of modern political scientists from explaining why people don't vote to explaining why they do.

This summary pays greatest attention to chapters 3 and 14 of Downs's book.

The Basic Logic of Voting

Downs starts from this basic model: In a world of perfect information, each voter would compare his expected utility of having party A (incumbent) in government (for another term, that is) with the expected utility of having party B (opposition) in government. This utility differential would determine each voter's choice at the ballot box.

But several problems force modifications of this model. Consider a typical voter:

1. He doesn't really know what the future holds, so he doesn't know which party's rule will give him greater utility (in the future). So instead, he will instead compare the utility he got over the last term from party A with what he thinks party B would have provided under the same circumstances; if he thinks party B would have brought him more utility, he votes for B. This is retrospective voting; see Fiorina (1981) and Key (1966).
2. He doesn't just look at raw utility differential, though; he also considers the trend. Is A getting better or worse? If it is getting better, then the voter will forgive A for early failures to deliver utility.
3. If A and B would have provided equal utility, the voter asks himself whether B would have used identical approaches and policies as A, or different ones?
   • If B would have been identical, the voter is indifferent and abstains.
   • If B would have provided equal utility but by different means, then the voter concludes: "Okay, a vote for B is a vote for something to change, but a vote for A is a vote for no change." He then must evaluate whether change (generally) is a good thing. To make this evaluation, performance evaluations come into play. Based on the history he has seen of various parties governing in various circumstance, he asks himself, "How much utility would the ideal government have delivered me under the circumstances that A has governed in?" If A stacks up well in comparison, he votes against change (i.e. for A). If not, he votes for change (i.e. for B) and hopes for the best.

These decisions about utility, however, lack perfect information. He must estimate all these questions about utility based on the "few areas of government activity where the difference between parties is great enough to impress him" (46). In other words, voters use information shortcuts; see Lupia and McCubbins (1998) for more.

In multiparty systems, the same line of thinking works, but with one qualifier: voters may act strategically. That is, they may vote for a party other than their favorite in order to keep a particularly disliked party out of office. Downs also leaves room for other types of strategic voting (like voting for a small party to give it a better chance next time, or something). For more on strategic voting, see Cox (1997).

Voter Turnout

Voting is costly--not only because of the information costs mentioned previously, but also because of the physical costs of getting to the polling place and taking time off work to do so. This leads to a conclusion that rational voters will rarely turn out to vote.

The benefits of turning out can be understood in terms of the "party differential" mentioned previously. But these benefits are weighted by the infinitesimal probability that one vote will determine the outcome. As such, even small voting costs make turnout irrational.

Downs seems perplexed by this result, since it clearly predicts much lower turnout than actually occurs. He suggests that voters might turn out simply to support democracy, knowing that democracy cannot survive long with zero turnout. However, Downs fails to recognize that even this "solution" fails to resolve the dilemma, since one person's decision of whether to support democracy has almost no probability of determining whether democracy succeeds.

See Riker and Ordeshook (1968) for more on this conclusion of zero turnout.