Consider the market for jeans and shoes. If the price of jeans decreases, we can illustrate this graphically by:

A)Rotating the budget constraint outwards on the "jeans" axis

B)Shifting the budget constraint inwards

C)Rotating the budget constraint inwards on the "jeans" axis

D)Shifting the budget constraint outwards

In the long run, which of the following must be true?

A) firms will not have any (total) fixed cost

B) variable costs must be the same as the variable costs in the short run

C)firms cannot change the labor inputs

D) firms cannot alter the scale of their operations

Alan got two tickets to the Maroon 5 concert. He has two choices: 1) Sell one ticket and get money; or 2) Go to the concert with his roommate, David. He gave one of tickets to David. After the concert, David bought him a nice dinner. We call this tendency _____.

A) Altruism

B) Reciprocity

C) Perceptions of others

D) Money