If you review the results of an IMPLAN economic impact study, you will not find GDP listed in the results. Naturally the question arises, "What is the GDP?" Within IMPLAN results, that value is actually demonstrated in multiple ways.
Gross Domestic Product (GDP) is defined as the total market value of all final goods and services produced within a region in a given period of time (usually a quarter or year). GDP is the sum of value added at every stage of production (the intermediate stages) for all final goods and services produced within a region in a given period of time. In other words, GDP is the wealth created by industry activity.