Labor Economics 5th Edition by George Borjas

Exercise 20

A worker plans to retire at the age of 65, at which time he will start collecting his retirement benefits. Then there is a sudden change in the forecast of inflation when the worker is 63 years old. In particular, inflation is now predicted to be higher than it had been expected so that the average price level of market goods and wages is now expected to be higher. What effect does this announcement have on the person's preferred retirement age:
(a) If retirement benefits are fully adjusted for inflation
(b) If retirement benefits are not fully adjusted for inflation