No attempt has been made, or formally recommended, to collect statistical data on INGOs and their members. Although data is collected on individuals (via the census), on commercial bodies and on each nation, none is collected on the bodies through which individuals express themselves or via which their views are moulded. As a consequence, attention is switched to socio-economic considerations and away from the variety of concerns represented by INGOs and their members.
This is particularly evident in the statistical data published in the various yearbooks of the UN system. Typically the ILO Yearbook of Labour Statistics has no details about trade unions, despite the amount of aggregated data on employees. The data on INGOs published in the Yearbook of International Organizations does not extend beyond INGOs as such in order to show the amount of national organization from which such international activity emerges. The absence of such data prevents its consideration as part of any battery of social indicators, given that it may be argued that the degree of organization of a society is an important measure of social development.