The 1993 SNA includes four classifications of expenditure according to purpose: Classification of the Functions of Government (COFOG); Classification of Individual Consumption According to Purpose (COICOP); Classification of the Purposes of Non-Profit Institutions Serving Households (COPNI); and Classification of the Outlays of Producers According to Purpose (COPP).

Although each classification is designed to provide sector-specific detail of analytic interest, these classifications also contain a number of broad socio-economic purposes in common. This paper asks whether we should be thinking in terms of a single integrated purpose classification instead of separate ones and explores the potential advantages of such a system.