Cost minimization requires that a firm equate the ratio of marginal products of inputs to the ratio of input prices

Paul and Maggie advertise for a babysitter. Jenny is the only one who answers the ad and she's hired. She asks for $7 per hour and gets it. She occasionally thinks of raising the rate to $10 but is afraid that Paul and Maggie will decide to advertise again. This tale is analogous to

a. monopolistic competitive pricing b. the idea of nationalization c. contestable markets d. laissez-faire e. creative destruction

The benefits principle is used to justify

a. sales taxes. b. gasoline taxes. c. "sin" taxes on cigarettes and alcoholic beverages. d. personal income taxes.