Social contributions are actual or imputed payments to social insurance schemes to make provision for social insurance benefits (see Section 17). They may be made by employers on behalf of their employees or by employees, self-employed or non-employed persons on their own behalf. The contributions may be compulsory or voluntary and the schemes may be funded or unfunded. Compulsory social security contributions paid to general government or to social security funds under the effective control of government form an important part of government revenue and, although they are not treated so in the SNA, many analysts (including the OECD’s Tax Directorate) consider the payments as being analogous to a tax on income and so part of a country’s overall tax burden. They are important not only in the sense that they form a significant share of government revenue but because they also reflect part of the costs of doing business. In many developing countries high social contributions coupled with low social benefits are often cited as a reason for a large informal economy.