135 In agriculture the existence of two forms of insurance may be necessary: one concerned with agricultural produce, the other with the farm workers and their families. We realize that agricultural workers earn less per capita than workers in industry and the services, but that is no reason why it should be considered socially just and equitable to set up systems of social insurance in which the allowances granted to farm workers and their families are substantially lower than those payable to other classes of workers. Insurance programs that are established for the general public should not differ markedly whatever be the economic sector in which the individuals work or the source of their income.
Source: Mater et Magistra (Vatican.va)