How would each of the following factors be likely to affect the economy-wide supply of labor?
a. The age at which people are eligible for Medicare is increased.
b. Increased productivity causes real wages to rise.
c. War preparations lead to the institution of a national draft, and many young people are called up.
d. More people decide to have children (consider both short-term and long-term effects).
e. Social Security benefits are made more generous.