Material flows

The Material Flow Accounts provide an aggregate overview, in thousands of tonnes per year, of the material flows into and out of an economy. It includes all the materials (except for water and air) that go beyond the boundaries of the system between the environment and the economy.

Domestic extraction (DE): DE indicates the total amount of material extracted by resident units from the natural environment for further processing in the economy.

Domestic material consumption (DMC):: DMC indicates the total amount of material actually consumed domestically by resident units. DMC of a given country's national economy can be calculated as the sum of domestic extraction plus physical trade balance.

Imports (IMP): Purchases of materials (raw materials, goods and products) in their simple mass weight.

Exports (EXP): Sales of materials (raw materials, goods and products) in their simple mass weight.

Physical trade balance (PTB): : Difference between imports and exports of materials (raw materials, goods and products). There are two kinds for Catalonia:

• With the rest of the State. The materials, goods or products purchased are shipped from or to the Spanish State.
• With foreign countries. The materials, goods or products purchased are shipped from or to foreign countries.

The Material Flow Accounts are closely related to the concepts and definitions of the national accounts. Thus, with regard to the physical boundaries of the economic system, the definition of the reference system is based upon the residence criterion (for resident production and consumption units, with the centre of economic interest in Catalonia) and not upon the basis of the territory criterion, which records operations that take place within particular administrative boundaries.