This paper reports the general results of research undertaken by Cenus Bureau staff. The views expressed are attributable to the authors and do not necessarily reflect those of the U.S. Census Bureau.

The Survey of Income and Program Participation (SIPP) is a complex longitudinal survey conducted by the Census Bureau to provide information for U.S. policy makers and academic researchers on topics such as poverty, government program participation and eligibility, health insurance coverage and income distributions.  Beginning in 1996, the SIPP will go into the field with a redesigned sample based on 1990 Decennial Census information, with oversampling for the low income population and with computer assisted personal interviewing (CAPI). Longitudinal samples will cover 4 years and have an abutting design rather than the current 2 2/3 year overlap design.

The current SIPP overlap design reduces the effects of panel biases for cross-sectional estimation.  However, the current longitudinal samples are not large enough to measure important phenomena such as long-term spells of poverty. During redesign planning the Census Bureau determined that longitudinal goals are the most critical for the SIPP program. As a result, a non-overlapping design of larger, longer panels was approved for SIPP redesigned samples.