The first international step towards the classification of workers by “status in employment” was taken in 1938 by the Committee of Statistical Experts of the League of Nations, which recommended the classification of the employed population into four status in employment categories, namely, “employers”, “own account workers”, “unpaid family workers” and “paid employees”. The same four categories were later recommended by the Sixth International Conference of Labour Statisticians in 1947 and by the Eight International Conference of Labour Statisticians in 1954.

In 1950 the Population Commission of the United Nations adopted standard definitions for these categories. A further group was added in 1958 in the recommendations concerning population censuses approved by the Statistical Commission of the United Nations, namely “members of producers’ cooperatives”.