Mary is willing to pay $50 for a Christmas tree, John is willing to pay $45 and Jeff is willing to pay $40. The price of a tree is $40. The total consumer surplus for Mary, John and Jeff taken together is

When an economy operates efficiently,

a. the MRPs of every input into the production of a good are equal. b. marginal utility equals marginal cost for every good. c. the price of a good equals the sum of the marginal physical products of its inputs. d. All of the above are correct.

Which of the following is an example of a decrease in government purchases? a. The government cancels an order for new military equipment

b. The Federal Reserve sells government bonds. c. The government increases personal income taxes. d. The government decreases unemployment insurance benefit payments.