The above classification for products and resources constitutes a tacit model of production, called the Static or formal model of production. In addition to macroeconomics, a version of the Static model has also been used as the main model in accounting and financial analysis of projects. Costs include the cost of acquired materials and supplies, cost of labor , and overhead which covers the depreciation of the used capital. These three main sources of costs correspond to the three factors of production in the Static model. In this structure, the outputs are also labeled as goods and services .
Gross profit is the difference between revenues and costs.
This formation has also been presented here. Obviously there exist many commonalties between the variables in the both versions of the Static model. However the economic studies, as well as accounting practices, have rarely studied the structure of the common model being used by both disciplines. Ammer argues that to the mercantalists emphasis on trade and to the physiocrats emphasis on agriculture, the classical economists added industry, which they felt was equally productive. They took into account neither the increasingly inequitable distribution of wealth and not the realities of technological change.