As the Federal Reserve ________ bonds, interest rates fall and the price of bonds ________

In an economic model, an endogenous variable is

A) a stand-in for more complicated variables. B) determined by the model itself. C) determined outside the model. D) a variable that has no effect on the workings of the model.

The decreasing portion of a firm's long run average cost curve is attributable to:

a. economies of scale. b. diseconomies of scale. c. increasing marginal cost. d. constant returns to scale.