The figure below shows the national market for mopeds in a country. Dd and Sd are the domestic demand and supply curves of mopeds, respectively.Calculate the welfare loss arising from the production effect of the tariff.

For a certain firm, the 100th unit of output that the firm produces has a marginal revenue of $11 and a marginal cost of $10 . It follows that the

a. production of the 100th unit of output increases the firm's profit by $1. b. production of the 100th unit of output increases the firm's average total cost by $1. c. firm's profit-maximizing level of output is less than 100 units. d. production of the 101st unit of output must increase the firm's profit by more than $1.

Which of the following is not an example of a barrier to entry?

a. Mighty Mitch's Mining Company owns a unique plot of land in Tanzania, under which lies the only large deposit of Tanzanite in the world. b. A college student starts a part-time tutoring business. c. A novelist obtains a copyright for her new book. d. A taxi cab driver in New York City obtains a license to legally provide transportation in New York City.