In planning domestic policy, the Federal Government needs information about the distribution of income received directly as money or indirectly as in-kind benefits (food stamps, Medicaid, we1fare, etc.) and the effects of tax and transfer programs on this distribution. Current data programs did not sufficiently meet this need. As a result, the Survey of Income and Program Participation (SIPP) was designed to provide data on the income and economic situation of the U.S. population on a continuing basis so that levels of economic well-being and changes in these levels can be measured over time.