Table 2 presents for each site the sample size and the "sample intake period" - that is, the dates from which the samples were drawn. The sample intake period for the three evaluation sites consists of the months in which welfare applicants and recipients were randomly assigned to program and control groups. We selected intake periods for the Urban Change sites to mirror those from the random assignment evaluations in order to make the analyses across these disparate samples more comparable. That is, for the Urban Change sites, the sample intake months correspond roughly to the months of random assignment for the three evaluation sites. In these sites, the month of sample intake is the first month within the designated intake period in which the individual received a welfare payment.
The analyses focus on a large subgroup of the five evaluation samples. Specifically, the sample for this report includes single parents (usually, mothers) aged 18 to 59 at sample intake who received at least one welfare payment during or after their month of sample intake. Welfare recipients excluded from this analysis include: (1) single parents younger than 18 or older than 59 years of age at sample intake; (2) members of two-parent welfare cases; and (3) adult caretakers of Child-Only or Foster Care assistance cases.(6) Together, these excluded groups made up between 20 and 30 percent of the welfare caseload in these sites.(7)
In the two Urban Change sites, Cleveland and Philadelphia, all welfare recipients who met the criteria listed above were included in the research samples. In contrast, the samples in the three evaluation sites are somewhat less representative of their respective caseloads in that they also exclude welfare recipients who were determined by welfare agency staff members to be exempt from their welfare program's requirement to participate in pre-employment activities. Exempted single parents included (1) incapacitated or disabled adults; (2) parents of a child under the age of one year (6 months of age in Florida FTP); and (3) adults caring for a disabled child or other dependent relative. These groups represent another 12 to 20 percent of the caseload.(8) Finally, most analyses in this report exclude sample members randomly assigned to the control group, which made up a quarter of the sample in Vermont WRP and half in Connecticut Jobs First and Florida FTP.(9)
|Survey Sample||Sample for Testing
Effects of PRWORA
|Connecticut Jobs First||Manchester and New Haven|
|Sample intake period||1/96 - 2/97||--||4/96 - 1/97||--|
|Florida FTP||Escambia County|
|Sample intake period||5/94 -2/95||5/94 -09/94||8/94 - 2/95||--|
|Sample intake period||7/94 -6/95||7/94 -6/95||10/94 - 6/95||--|
|Urban Change sites|
|Sample intake period||7/94 - 12/96||7/94-01/96||7/94 - 10/95||1/93-12/96|
|Sample intake period||1/94 - 12/97||1/94-12/96||1/94 - 7/95||1/93-12/97|
|Total sample size||161,007||146,151||4,285||75,432|
| Sources: MDRC calculations from state and county administrative records, Background Information Forms, and survey responses.
Notes: Sample sizes for the evaluation sites include program group members only. Control group members number: Connecticut Jobs First: 2,102; Florida FTP: 1,124; and Vermont WRP: 1,004. Control group members are excluded from all calculations except those displayed on Table 12.
The study sample is limited to single-parent adults, ages 18 to 59, meeting study criteria.
Table 2 shows reasonable sample sizes for the random assignment evaluations and large sample sizes for the non-experimental Urban Change sites. Sample intake took place during 1994 through 1997 and varied in duration from 10 months in Vermont WRP to 48 months in Philadelphia.
As shown in Table 2, the report calculates the incidence of cycling and other outcomes for several different subsamples. The largest sample, called the full sample, is used for most analyses in this report. The full sample includes 161,007 members from the five sites who met the sample selection criteria described above. Each member of the full sample has employment and welfare data, collected from administrative records, from two years before through at least four years after her month of sample intake.
The five-year follow-up sample includes the 146,151 members (about 91 percent) of the full sample who have employment and welfare data for at least five years following their month of sample intake. This sample is used for the analyses of employment and welfare outcomes in year 5 after sample intake.(10) Table 2 shows that all members of the full sample in Vermont WRP have administrative data for five years after sample intake, as do more than 90 percent of the full sample from Cleveland and Philadelphia. In contrast, the five-year follow-up sample includes only 535 full sample members (about 47 percent) from Florida FTP and no full sample members from Connecticut Jobs First.
The survey sample consists of the 4,285 members of the full sample who completed survey interviews between 36 and 60 months after their date of sample intake. The survey sample includes respondents from all five sites and is used for analyses of outcomes such as household income, household composition, job characteristics, and material hardships, which were unavailable from administrative data.
The strategies for fielding a survey sample varied somewhat in the three evaluation sites.(11) However, in each evaluation site, survey respondents were chosen from nearly all months of sample intake. This strategy increased the likelihood that results for survey respondents could be generalized to the full samples in these sites.
In contrast, for the Urban Change sites, a more specialized sampling design was followed in which respondents were selected from among all recipients of welfare or food stamps benefits in each site during a single month, May 1995. In both Cleveland and Philadelphia, this month falls toward the beginning of the sample intake period for this report. By definition, this sampling strategy excludes members of the full sample who did not receive welfare or food stamps benefits in May 1995 - either because they had already left assistance by that date or because they had not yet applied. As a result, the survey samples in Cleveland and Philadelphia are somewhat less representative of the full samples, compared with the samples in the three evaluation sites.
Finally, we use a special sample from the Urban Change sites to evaluate the effects of PRWORA on the likelihood of becoming a cycler.(12) This sample for testing the effects of PRWORA includes full sample members who had received their first welfare payment between January 1993 (the first month of available data)(13) and their month of sample intake. That is, they were either first-time applicants for welfare benefits at their time of sample intake or they had received welfare for the first time between January 1993 and their sample intake date. This sample for testing the effects of PRWORA also includes recipients not in the full sample. This additional "early cohort" was included to better detect the effect of welfare regulations on cycling during the years before PRWORA. The members of this early cohort first received welfare benefits on or after January 1993, but before the first month of sample intake for the full sample. For example, the early cohort includes those recipients who received their first welfare benefit between January 1993 and January 1994(14), but did not receive welfare benefits during the sample intake period. These samples are used since the longitudinal nature of the samples allows a quasi-experimental estimate of the effect of welfare reform. The early cohort members are not part of the full sample and are excluded from all other analyses in this report.
We analyze the effect of PRWORA separately in each Urban Change site. Table 2 shows that there are 26,365 and 49,067 members of this special sample in the Cleveland and Philadelphia, studies respectively.