Since 1802, the average annual compound return for stock holdings, adjusted for inflation, has been approximately

The figure above shows the market for a good with an external benefit. The efficient level of production is ________ units because ________

A) 8; marginal benefit equals marginal cost B) 8; marginal cost is less than marginal social benefit C) 10; marginal cost equals marginal social benefit D) 10; marginal social benefit exceeds marginal benefit E) 8; marginal benefit equals the marginal external benefit

If the demand for letters written by Abraham Lincoln is higher than the demand for letters written by John Wilkes Booth, what would have to be true for the market equilibrium prices for these letters to be equal?

A) The supply of Lincoln letters would have to be less than the supply of Booth letters. B) The supply of Booth letters would have to be less than the supply of Lincoln letters. C) The supply of Lincoln letters and the supply of Booth letters would have to be equal. D) If the demand for Lincoln letters is greater than the demand for Booth letters, the market equilibrium price for Lincoln letters will always be greater than the market equilibrium price for Booth letters.