A Treasury security with an original maturity of twenty years is called a

The difference between short-run and long-run cost is that in the long run,

a. there are shortages of labor that can restrict output b. only labor can be changed to increase or decrease production c. fixed factors of production have already been chosen d. there are no diseconomies of scale e. all factors of production are variable

A perfectly competitive firm should continue to expand output until

A. total revenue exceeds total costs. B. total revenue exceeds variable costs. C. marginal revenue equals marginal costs. D. average revenue equals variable costs.