Carbon dioxide emissions are thought to contribute to global warming, and there is a concern that changes in climate will be costly. Emitting carbon dioxide is an example of:

Suppose an economy produces milk and honey, and milk is plotted along the horizontal axis of the production possibilities frontier. The MRT is 2 at the current point of production

If the amount of milk produced is reduced by two units in order to produce one more unit of honey, then: A) the new point of production lies above the production possibilities frontier. B) the new point of production lies on the production possibilities frontier. C) the new point of production lies below the production possibilities frontier. D) we cannot determine where the new point of production lies relative to the production possibilities frontier.

The reward for forgoing present consumption is

a. rent b. profit c. roundabout production d. transfer payment e. interest