Suppose there are 100 firms in an industry. If the leading firm has a 60 percent market share, the second largest firm has a market share of half the leader's, the third has a market share of half the second's, and the fourth largest has a market share of half the third's, what is the four-firm concentration ratio?

Which of the following is NOT a reason the Fed changes the rate of growth of the money supply?

A) to influence the amount of consumption B) to influence the amount of investment C) to shift the demand for money curve D) to influence aggregate demand

A rent ceiling results in a shortage of apartments. As a result, there is

A) only a loss of consumer surplus for tenants. B) only a loss of producer surplus for landlords. C) a loss of both consumer and producer surplus. D) a gain of both consumer and producer surplus.