DEFINE-MATTER is a simplified module of DEFINE that shows how economic activity leads to the extraction of matter and the generation of waste. In the model, when production takes place, a specific amount of matter is necessary. This matter can be either extracted from the environment or come from recycling. When matter is extracted, the material reserves (i.e. those volumes of matter expected to be produced economically using the existing technology) tend to decline.

The production process generates consumption and investment goods that are accumulated in the socio-economic system. The material content of these goods is called ‘socio-economic stock’. A part of this socio-economic stock is demolished/discarded every year. Through waste management, a proportion of demolished/discarded socio-economic stock is recycled. The rest of it becomes waste that is discarded to the environment. Part of this waste is hazardous and can have negative effects both on the environment and the health of the population.

A brief description of the DEFINE-MATTER module is available is available here. The R code of the module can be downloaded here.