The prevalence and persistence of poverty are central issues in both “Welfare Reform” and the “War on Poverty.” Providing both snapshots and videos of poverty from various perspectives, data from the 1993 panel of the Survey of Income and Program Participation (SIPP) picture poverty primarily as a transitory condition for many and a chronic condition for some. Poverty rates are like snapshots: they describe the percentage of people who are poor for a specified period of time. Poverty spells and transitions, in contrast, are like videos: they show how long people stay poor, as well as movements into and out of poverty. These diverse statistics provide a richer picture of poverty than does a single annual rate. Reflecting diverse viewpoints, “War on Poverty” proponents may emphasize how many individuals experience any episode of poverty and the duration of the episodes, but “Welfare Reform” advocates may focus primarily on people who are chronically poor. Both groups are likely to examine transitions into and out of poverty.

This report uses data from the 1993 SIPP panel to examine poverty from October 1992 through December 1995.¹ SIPP allows us to examine both the static and dynamic aspects of poverty, thereby providing a richer picture than the one drawn by the Current Population Survey (CPS), the survey currently used for official poverty rates. The CPS provides only a single static snapshot of poverty for the population. SIPP’s longitudinal data provide not only several static pictures but also several dynamic measures of movement into and out of poverty and poverty spells or duration. In addition, SIPP can also distinguish between short-term and long-term poverty. Unlike the CPS’ annual data, the SIPP uses monthly data to measure poverty; hence, the SIPP allows one to measure poverty on a monthly basis as well as for longer periods of time.

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¹ The longitudinal estimates presented here are based on people who either were interviewed in all waves of the reference period, or for whom imputed information exists. Efforts were made during the life of the panel to ensure that the sample remained representative of the noninstitutional population of the United States. People who moved were followed to their new address. A “missing wave imputation” procedure was used for people who missed an interview but had completed interviews before and after the missing wave. If the people included in the estimates have different experiences of poverty than do the people who did not respond initially, left the sample, or missed two or more consecutive waves, these longitudinal estimates may be biased.

All statistics are subject to sampling error, as well as nonsampling error such as survey design flaws, respondent classification and reporting errors, data processing mistakes, and undercoverage. The Census Bureau has taken steps to minimize errors in the form of quality control and edit procedures to reduce errors made by respondents, coders, and interviewers. Ratio estimation to independent age-race-sex population controls partially corrects for bias attributable to survey undercoverage. However, biases exist in the estimates when missed people have characteristics different from those of interviewed people in the same age-race-sex group.

Analytical statements in this report have been tested and meet statistical standards. However, because of methodological differences, use caution when comparing these data with data from other sources. More detailed tabulations on these measures can be found at the Census Bureau's internet site at <www.census.gov>.