Glossary
Non-use values, also referred to as Òpassive useÓ values – values that are not associated with actual use, or even the option to use a good or service.

Opportunity Cost – The value of the best alternative to a given choice, or the value of resources in their next best use.  In regard to time, the opportunity cost of time spent on one activity is the value of the best alternative activity that the person might engage in at that time.

Option value – the value that people place on having the option to enjoy something in the future, although they may not currently use it.

Producer surplus – the difference between the total amount earned from a good (price times quantity sold) and the production costs.

Public goods – goods that may be enjoyed by any number of people without affecting other peoplesÕ enjoyment.  For example, an aesthetic view is a pure public good.  No matter how many people enjoy the view, others can also enjoy it.