social insurance, publicinsurance program that provides protection against various economic risks (e.g., loss of income due to sickness,old age, or unemployment) and in which participation is compulsory. Social insurance is considered to be a type ofsocial security (q.v.), and in fact the two terms are sometimes used interchangeably.

The first compulsory social insurance programs on a national scale were established inGermany under ChancellorOtto von Bismarck:health insurance in 1883,workmen’s compensation in 1884, and old-age and invalidity pensions in 1889. Germany’s example was soon followed by Austria and Hungary. The issue of social insurance elsewhere in Europe was dominated by a debate between those who preferred voluntary, subsidized insurance and those who advocated a compulsory system. GreatBritain adopted national compulsory health insurance in 1911 and greatly expanded it in 1948. After 1920, social insurance on a compulsory basis was rapidly adopted throughout Europe and in theWestern Hemisphere. TheUnited States lagged behind Europe; until 1935, with the passage of theSocial Security Act, government insurance programs were exclusively the responsibility of state or local governments. The three federal insurance programs adopted in the United States since 1935 provide retirement and survivor benefits, health care for persons over 65, and insurance against disability.

Social insurance programs differ from private insurance in several ways. Contributions are normally compulsory and may be made by the insured’s employer and the state, as well as by the insured himself. Also, benefits are not as strictly tied to contributions as in private insurance. For example, to make the programs serve certain social purposes, some groups are included among beneficiaries even though they have not contributed for the required periods of time. Benefits may be raised in response to increases in thecost of living, again weakening the link between contributions and benefits.

Social insurance, however, differs significantly from other forms of public aid. Social insurance systems tend to be self-financing, with contributions placed in specific funds for that purpose. Because the payment of benefits is based generally on contributions made and not on need, the necessity for ameans test is removed. Benefits become a right, and any stigma attached to receiving public funds is reduced. In certain countries, social insurance programs resemble private insurance in that the required contribution levels reflect varying degrees ofrisk. For example, contributions tounemployment insurance programs for employers with low discharge and layoff rates may be less than for those with higher rates.

There are considerable variations among countries in the financing of social insurance programs. Australia, Sweden, and Denmark are among those in which the state bears a high proportion of the costs. The distribution of costs also varies within each country according to the particular program in question. For instance, it is common for employers to bear the full cost of workmen’s injury insurance.See alsosocial welfare program.