Most economies in the world are

At its current production level, a monopolist's marginal revenue is $20 and its marginal cost is $10. Which of the following is CORRECT?

a. The monopolist should produce and sell more output. b. The monopolist should produce and sell less output. c. The monopolist is maximizing its profits at its current level of output. d. More information is required to decide if the firm needs to change its production.

When total planned real expenditures change due to changes in the cost of borrowing that result from variations in the price level, this is known as the

A) interest rate effect. B) real-balance effect. C) open economy effect. D) aggregate balances effect.