Which of the following categories accounted for the third largest percentage of total federal government expenditures?

Common pool resources differ from pure public goods in that

A) common pool resources are resources that cannot be renewed but the production of pure public goods can be increased at any time. B) common pool resources are nonexcludable while pure public goods are excludable to those who do not pay of the good. C) unlike pure public goods, common pool resources are rival in consumption. D) common pool resources are collectively owned by a group of people while pure public goods are owned by the government.

Along a straight-line downward-sloping demand curve, elasticity is

a. constant, but its value cannot be determined without measurement b. constant and equal to an absolute value of one c. greater at higher prices d. greater at lower prices e. greater in the middle