A modern open economy like that of Northern Ireland engages in four basic economic activities:
Production involves industries producing goods and services.
Consumption represents purchases of goods and services by both industries and domestic final users comprising mainly households and Central and Local Government.
Accumulation involves all capital transactions including all fixed investment expenditure and changes in the level of stocks.
Trade involves imports from, and exports to, Great Britain and the rest of the world (RoW).
Measurement of these four activities is captured in the framework of the Supply-Use Tables. The resulting tables serve a number of purposes, all of which contribute in different ways to understanding the Northern Ireland economy. The framework is illustrated below.
In broad terms, the output and supply table allows the user an appreciation of the absolute monetary values of each industry's output for a given calendar year. Additionally, and possibly more importantly, this table also presents the relationships between the output of products and the output of industries - e.g. key statistics are produced on the extent of diversification within industries and the extent of competition between industries producing the same product.
The combined use matrix shows the consumption of products (goods and services) and primary inputs, in terms of combined domestic and imported goods and services, used in each industry's production process and, in doing so, presents a comprehensive description of the domestic production functions of Northern Ireland industries. This table also gives detailed purchasing information by final consumers.