Gary J. Bass in the New York Times Magazine:
…Bryan Caplan, an economist at George Mason University, has attracted notice for raising a pointed question: Do voters have any idea what they are doing? In his provocative new book, “The Myth of the Rational Voter: Why Democracies Choose Bad Policies,” Caplan argues that “voters are worse than ignorant; they are, in a word, irrational — and vote accordingly.” Caplan’s complaint is not that special-interest groups might subvert the will of the people, or that government might ignore the will of the people. He objects to the will of the people itself.
In defending democracy, theorists of public choice sometimes invoke what they call “the miracle of aggregation.” It might seem obvious that few voters fully understand the intricacies of, say, single-payer universal health care. (I certainly don’t.) But imagine, Caplan writes, that just 1 percent of voters are fully informed and the other 99 percent are so ignorant that they vote at random. In a campaign between two candidates, one of whom has an excellent health care plan and the other a horrible plan, the candidates evenly split the ignorant voters’ ballots. Since all the well-informed voters opt for the candidate with the good health care plan, she wins. Thus, even in a democracy composed almost exclusively of the ignorant, we achieve first-rate health care.
The hitch, as Caplan points out, is that this miracle of aggregation works only if the errors are random.
More here.