Answer:
increases in entitlement programs
Step-by-step explanation:
Entitle programs refers to the collection of benefit that is given by all legal citizens by the government. (such as health care, government funded scholarships, government backed loan , etc).
Since the money to pay for the programs come from the government fund, it is considered as government expenditures. The number of population in united states keep increasing since 1960, so this will lead to a gradual increase to the federal government expenditures.