Answer:
12. B) Expected inflation for the current year was approximately equal to the previous year's inflation rate. This assumption was known as adaptive expectations and was widely used by economists to explain how individuals formed their expectations about future inflation rates.
13. C) remained constant at zero. This equation shows that individuals' expectations of current inflation are based on their expectations of inflation in the previous period. A value of zero means that individuals assume that current inflation will be equal to past inflation, on average.
14. B) nominal wages will be set for shorter periods of time. When inflation is low and stable, there is less pressure for employers to adjust wages frequently to keep up with rising prices. This means that nominal wages can be set for shorter periods of time, without the risk of losing purchasing power due to inflation.
15. C) Individuals changed the way they formed expectations of inflation. The original Phillips curve showed an inverse relationship between unemployment and inflation, but this relationship began to break down in the 1970s. One explanation for this is that individuals began to form their expectations of inflation differently, using more sophisticated methods such as rational expectations. This made it more difficult for policymakers to use monetary policy to stabilize the economy.