Explain how the following actual design features have an important effect on the consequences of government programs:

a. The income ceiling for eligibility for SNAP benefits is reduced by expenditures on housing.

b. Until recently, whether an individual between the ages of 65 and 70 was eligible for Social Security benefits depended on his or her income calculated on a month-by-month basis.

c. An ex-spouse becomes eligible for Social Security benefits only if the marriage lasted at least 10 years.