Consider two models for estimating, in advance of an election, the shares of votes that will go to rival candidates. According to one model, pollsters’ surveys of a randomly chosen set of registered voters before an election can be used to forecast the percentage of votes that each candidate will receive. This first model relies on the assumption that unpaid survey respondents will give truthful responses about how they will vote and that they will actually cast a ballot in the election. The other model uses prices of financial assets (legally binding IOUs) issued by the Iowa Electronic Markets, operated by the University of Iowa, to predict electoral outcomes. The final payments received by owners of these assets, which can be bought or sold during the weeks and days preceding an election, depending on the shares of votes the candidates actually end up receiving. This second model assumes that owners of these assets wish to earn the highest possible returns, and it indicates that the market prices of these assets provide an indication of the percentage of votes that each candidate will actually receive on the day of the election.
(a) Which of these two models for forecasting electoral results is more firmly based on the rationality assumption of economics?
(b) How would an economist evaluate which is the better model for forecasting electoral outcomes?
