1.66 . The aggregates are composite values which measure the result of the activity of the total economy considered from a particular point of view; for example, output, value added, disposable income, final consumption, saving, capital formation, etc. Although the calculation of the aggregates is neither its sole nor its main purpose, the system does recognise their importance as summary indicators and key magnitudes for purposes of macro-economic analysis and comparisons over time and space.
Two types of aggregates can be distinguished:
a) aggregates which refer directly to transactions in the system, such as the output of goods and services, actual final consumption, gross fixed capital formation, compensation of employees, etc.;
b) aggregates which represent balancing items in the accounts, such as gross domestic product at market prices (GDP), operating surplus of the total economy, national income, national disposable income, saving, current external balance, net worth of the total economy (national wealth).
1.67 . A dimension is added to the usefulness of a number of national accounts figures by calculating these figures per head. For broad aggregates such as GDP or national income or household final consumption, the denominator commonly used is the total (resident) population. When sub-sectoring the accounts or part of the accounts of the household sector, data on the number of households and the number of persons belonging to each sub-sector are also necessary .