is not included in calculating gross domestic product (GDP). An Australian study has shown the value of this uncounted work to be approximately 50% of GDP, making its exclusion rather significant. As GDP is tied closely to the national accounts system, this may lead to a distorted view of national accounts. Because national accounts are widely used by governmental policy-makers in implementing controllable economic agendas, some analysts have advocated for either a change in the makeup of national accounts or adjustments in the formulation of public policy. History The original motivation for the development of national accounts and the systematic measurement of employment was the need for accurate measures of aggregate economic activity. This was made more pressing by the Great Depression and as a basis for Keynesian macroeconomic stabilisation policy and wartime economic planning. The first efforts to develop such measures were undertaken in the late 1920s and 1930s, notably by Colin Clark and Simon Kuznets. Richard Stone of the U.K. led later contributions during World War II and thereafter. The first formal national accounts were published by the United States in 1947. Many European countries followed shortly thereafter, and the United Nations published A System of National Accounts and Supporting Tables'' in 1952. International standards for national accounting are defined by the United Nations System of National Accounts, with the most recent version released for 2008. Even before that in early 1920s there were national economic accounts tables. One of such systems was called Balance of national economy and was used in USSR and other socialistic countries to measure the efficiency of socialistic production. In Europe, the worldwide System of National Accounts has been adapted in the European System of Accounts (ESA), which is applied by members of the European Union and many other European countries. Research on the subject continues from its beginnings through today. See also Accounting identity Aggregation problem European System of Accounts Measures of national income and output Material Product System National Income and Product Accounts (US) Official statistics Penn World Table Savings identity Sectoral balances Social accounting United Nations System of National Accounts References External links Economic data Official statistics