168 Answers to Textbook Questions and Problems
5. The problem of time inconsistency arises because expectations of future policies affect
how people act today. As a result, policymakers may want to announce today the policy
they intend to follow in the future, in order to influence the expectations held by pri-
vate decisionmakers. Once these private decisionmakers have acted on their expecta-
tions, the policymakers may be tempted to renege on their announcement.
For example, your professor has an incentive to announce that there will be a final
exam in your course, so that you study and learn the material. On the morning of the
exam, when you have already studied and learned all the material, the professor might
be tempted to cancel the exam so that he or she does not have to grade it.
Similarly, the government has an incentive to announce that it will not negotiate
with terrorists. If terrorists believe that they have nothing to gain by kidnapping
6. One policy rule that the Fed might follow is to allow the money supply to grow at a con-
stant rate. Monetarist economists believe that most large fluctuations in the economy
result from fluctuations in the money supply; hence, a rule of steady money growth
would prevent these large fluctuations.
A second policy rule is a nominal GDP target. Under this rule, the Fed would
announce a planned path for nominal GDP. If nominal GDP were below this target, for
example, the Fed would increase money growth to stimulate aggregate demand. An
Problems and Applications
1. Suppose the economy has a Phillips curve
u= un– α(π– Eπ).
As usual, this implies that if inflation is lower than expected, then unemployment rises
above its natural rate, and there is a recession. Similarly, if inflation is higher than
expected, then unemployment falls below its natural rate, and there is a boom. Also,
suppose that the Democratic party always follows a policy of high money growth and
high inflation (call it πD), whereas the Republican party always follows a policy of low