The “Big Mac Theory of Exchange Rates” tests the accuracy of purchasing power
parity theory. In July 2013, The Economist reported that the average price of a Big Mac
in the United States was $4.56. In Switzerland, the average price of a Big Mac at that
time was 6.50 Swiss francs. If the exchange rate between the dollar and the Swiss franc
was 0.93 Swiss francs per dollar, explain how it would be profitable to buy Big Macs in
the United States instead of in Switzerland.
Behavioral economists examine choices that consumers make that are not economically
rational. Economists generally assume that people are rational; that is, they weigh the
benefits and costs of an action and choose an action only if the benefits outweigh the
costs. Why do consumers not act rationally when the result is that they make
themselves worse off?