Data collected by surveys of individuals or firms. Surveys may be total in their coverage, as with censuses, or may be based on samples of the relevant population. They may be conducted by government bodies, either specifically set up for the purpose, for example the Office for National Statistics in the UK, or in the course of their normal work. Data on UK incomes, for example, are collected by HM Revenue and Customs, and data on trade by the Department for Business, Enterprise and Regulatory Reform. Surveys are also conducted by private commercial bodies such as market research firms, by private bodies such as the Confederation of British Industry, and by academic institutions.