According to the above table, if real Gross Domestic Product (GDP) is $25,000, planned saving equals

Marginal social cost is equal to ________

A) marginal private cost plus the marginal external cost B) the marginal external cost C) the value of the tax that will make the market efficient D) the marginal cost imposed on people other than the producer of the good

In the above figure, market equilibrium at point E yields the quantity X. The quantity X* is socially optimal amount. The government can achieve the optimal outcome by

A) setting the price at P1. B) establishing a tax of P3 - P1 per unit of the good sold. C) establishing a tax of P3 - P2 per unit of the good sold. D) setting the price at P4.