The table above shows sales of the firms in the pet food industry. The four-firm concentration ratio in the industry is

In a Nash equilibrium, each player takes the best possible action given the actions of the other players

Indicate whether the statement is true or false

Bob and Mary each have a Ph.D. in economics. Bob has a job in private industry at which he earns $90,000 a year. Mary earns half that much as a college professor. Which of the following could not explain Mary's career choice?

a. She experiences diminishing marginal utility. b. She enjoys the flexibility of her schedule. c. She enjoys teaching. d. She enjoys the informal atmosphere of a college. e. She likes having her summers free to do research.