The BP curve shifts to the left when:

The fact that the United States exports Budweiser beer and imports Heineken beer can be explained by:

a. the differences in labor productivity in the U.S. and other countries. b. the differences in factor endowments in the U.S. and its trading partners. c. the world price of Budweiser beer is lower than Heineken beer. d. the fact that production of Budweiser beer in the U.S. is inadequate compared to its demand. e. the preference for foreign brands of beer by a part of the U.S. population.

If an externality is created by a single person or firm, and affects only a single person or firm, then

a. it is referred to as a single externality b. the inefficiency caused by that externality may be resolved by those two parties c. the externality takes the form of a side payment d. Pareto efficiency is guaranteed e. fairness dictates that the externality be removed