CLASSICAL PUBLIC CHOICE
AND THE FAILURE OF RATIONAL
Apparently irrational cultural beliefs are quite remarkable:
They do not appear irrational by slightly departing from
common sense, or timidly going beyond what the
evidence allows. They appear, rather, like down-right
provocations against common sense rationality.
ANTHONY DOWNS'S An Economic Theory of Democracy (1957) turned rational ignorance into a basic element of the economics of politics. Gordon Tullock did not coin the phrase until 10 years later,2 but Downs's one-sentence explanation remains definitive: “it is irrational to be politically well-informed because the low returns from data simply do not justify their cost in time and other resources.”3
The logic is simple. Time is money, and acquiring information requires time. Individuals balance the benefit of learning against its cost.4 In markets, if individuals know too little, they pay the price in missed opportunities” if they know too much, they pay the price in wasted time. The prudent path is to find out enough to make a tolerably good decision.
Matters are different in politics. One vote is extraordinarily unlikely to change an election's outcome.5 So suppose an ignorant citizen votes randomly. Except in the freak case where he casts the decisive vote, flipping an otherwise deadlocked election, the marginal effect is zero. If time is money, acquiring political information takes time, and the expected personal benefit of voting is roughly zero, a rational, selfish individual chooses to be ignorant.
The civics textbook motto, “If everybody thought that way, democracy would produce horrible results,” could well be true. But as an appeal to citizen self-interest, the motto is a bald fallacy of composition. If everyone knows nothing about politics, we are worse off; but