If the marginal propensity to consume (MPC) is 0.9, the spending multiplier will be

Product differentiation exists within an industry if

A) there are no substitutes for a product. B) there are close but not perfect substitutes for a product. C) the firm can sell all it wants at the chosen price. D) there is a monopoly.

For a competitive equilibrium in a two-period model, all of the following must be true except

A) each consumer picks first- and second-period consumption given the real interest rate. B) there must be an equal number of borrowers and lenders. C) the government's present-value budget constraint holds. D) the credit market clears.