Refer to the above table. The four-firm concentration ratio is

An assumption that makes an economic model simpler without affecting its conclusions in important ways is

a. an indication of a positive assumption b. an efficient assumption c. useful in disguising the valid conclusions d. a simplifying assumption e. a critical assumption

Which of the following would NOT be included in this year's GDP?

A) the production of a television show
B) the purchase of a new work truck
C) the hiring of a new police officer
D) your purchase of your neighbor's 2001 Toyota