Debbie observes that leaves fall from trees before the fist day of winter, and concludes that the falling leaves cause winter to begin. This is an example of

A prisoner's dilemma exists for global pollutants because:

a. countries do not face the full cost of pollution that they generate. b. countries that regulate pollution gain more than countries that do not regulate pollution. c. countries that regulate pollution lose more than countries that do not regulate pollution. d. no country follows international agreements to limit pollution.

For a single-price monopolist, marginal revenue is less than price because

A) the revenue gain from the last unit sold is offset by a revenue loss on the units that previously had been sold at a higher price. B) the revenue gain from the last unit sold is offset by further gains in price on units not sold at all. C) total revenue always decreases as output increases. D) the price does not have to be lowered on all previous units sold.