Glossary
Substitute goods – goods that you might purchase instead of a particular good. For example, different types of bread are substitutes for each other.

Supply Function – the mathematical function that relates price and quantity supplied for goods or services.  The supply function tells how many units of a good that producers are willing to produce and sell at a given price. 

Supply Curve - the graphical representation of the supply function.  Because producers would like to sell more at higher prices, the supply function slopes upward.

Total economic value – the sum of all types of use and non-use values for a good or service.

Use value – value derived from actual use of a good or service.  Uses may include indirect uses.  For example, enjoying a television show about whales provides an indirect use value for the whales.

Variable costs – production costs that change when the level of production changes, so that when more is produced the costs increase; as opposed to fixed costs.

Willingness to Pay – the amount—measured in goods, services, or dollars—that a person is willing to give up to get a particular good or service.