Suppose that the price of a hamburger is $3. Victoria is willing to pay $5 for the first hamburger, David is willing to pay $4 for the second hamburger, Kelly is willing to pay $3 for the third hamburger, and Antony is willing to pay $2 for the fourth hamburger. In equilibrium, what is the number of hamburgers purchased?

The optimal amount of pollution abatement is such that

A) the total benefit of reducing pollution is equal to the total cost of reducing pollution. B) the marginal private cost of reducing pollution is just equal to the profit of the polluting firms. C) there is no remaining pollution. D) the marginal social cost of reducing pollution is just equal to the marginal social benefits from doing so. E) none of the above; there is no optimal amount of pollution abatement.

Suppliers recognize there is a shortage in the market for their product when they notice that

a. the quantity supplied exceeds the quantity demanded b. the quantity demanded is falling c. inventories are falling d. production exceeds new orders for the product e. government economists announce a shortage exists