Skip to main content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.


The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

National Evaluation of Welfare-to-Work Strategies: 2-Year Full Impact Sample Files: Research Design for the NEWWS Evaluation

 Research Design for the NEWWS Evaluation  To test the effectiveness of welfare-to-work program strategies, this evaluation uses an unusually strong research design: a random assignment experiment. In each evaluation site, individuals who were required to participate in the program were assigned, by chance, to either a program group, which had access to employment and training services and whose members were required to participate in the program or risk a reduction in their monthly AFDC grant, or a control group, which received no services through the program but whose members could seek out such services on their own from the community. This random assignment design assures that there are no systematic differences between the background characteristics of program and control group members when they enter the study. Thus, any subsequent differences in outcomes between the groups (called impacts) can be attributed with confidence to the effects of the program.  Four sites implemented a three-way random assignment research design in order to test the relative effectiveness of two different program approaches. In the three-way design, an individual is assigned, by chance, to either one of two program groups or a control group. Members of the two program groups and the control group are subject to the same labor market conditions and other environmental factors, assuring that any differences in outcomes between the two program groups, or between either program group and the control group, were caused by the programs' design and implementation.  Three of these four sites (Atlanta, Grand Rapids, and Riverside) ran two programs that used extreme versions of the employment- and education-focused approaches described in the previous chapter: a Labor Force Attachment (LFA) approach, which emphasizes that the workplace is where welfare recipients can best learn work habits and skills and thus tries to place people in jobs quickly, even at low wages; and a Human Capital Development (HCD) approach, which emphasizes education and training as a precursor to employment and invests in the "human capital" of welfare recipients to enable them to retain jobs and have a better chance of advancement.  In Riverside existing statewide rules mandated that only individuals who were "in need of basic education" - defined as not having a high school diploma or GED, having low scores on a welfare department math or reading literacy test, or requiring English-as-a-Second-Language instruction - could be assigned to the HCD group. The LFA group in that site, however, includes both those who were determined to be "in need" and those "not in need." For the measures included in this report, results for the segment of the LFA group in Riverside who were determined to be in need of basic education are included so that direct comparisons between the LFA and HCD groups in that site can be made. Further, direct comparisons between results of the Riverside HCD program and those of other programs in this evaluation can be made only with those who lacked a high school diploma or GED in the other programs.  Columbus used a three-way random assignment design to test the relative effectiveness of two different case management models. In the Traditional model the welfare department's employment and training and income maintenance functions are handled by two different workers, both of whom maintain relatively large caseloads; in the Integrated model one worker handles both the employment and income maintenance functions. The integrated worker maintains a smaller caseload than either of the traditional workers and is expected to provide more intensive services.  The remaining three sites in the evaluation (Oklahoma City, Detroit, and Portland) used random assignment to test the effectiveness of established programs. Instead of implementing a program designed to meet research protocols, as in the three-way sites, program administrators determined their welfare-to-work program goals and practices and randomly assigned individuals to either a group that entered the program or a non-program control group.  Individuals were randomly assigned to programs over approximately a two-year period in each site. Random assignment for the evaluation began in June 1991 in Riverside, California, and ended in December 1994 in Portland, Oregon. Thus, the results presented in the Two-Year files cover the calendar period from June 1991 (the first month of the first sample member's entry in the program) to December 1996 (the last month of a two-year follow-up for the last sample member randomly assigned in Portland).  The differences in procedures used to randomly assign clients in this evaluation affected the sample composition and, thus, comparability of the sites and programs. In five of the seven sites AFDC applicants and recipients who met the demographic criteria to be mandated to participate were randomly assigned while attending a program orientation at the employment and training office. In Columbus and Oklahoma City individuals were randomly assigned at the income maintenance office, before they were assigned to an orientation.  Not all individuals assigned to participate in welfare-to-work programs actually attend an orientation; some individuals who do not attend may leave the AFDC rolls shortly after being referred to the program, may have had their applications denied, or may not have a good reason for not attending.  For example, long waiting lists for orientation "slots" can create a situation in which the more employable individuals on the caseload can find jobs on their own and exit AFDC before being randomly assigned, leaving more "disadvantaged" individuals to enroll in the program. In three programs for which these data are available (Riverside, Grand Rapids, and the Columbus Traditional program) about two-thirds of those required to attend an orientation actually did so. The Columbus Integrated program, however, compelled about five-sixths of sample members to attend an orientation.  Because outcomes in this report are reported as averages for all sample members in a group, the different capacities of the Integrated and Traditional groups to enroll individuals are reflected in their participation and subsequent employment, earnings, and welfare outcomes.  Because Oklahoma City, unlike all other sites, randomly assigned only applicants, including those whose application for assistance was not yet approved, two points need to be considered. First, the impact estimates include a larger proportion of people who never received an AFDC payment after being randomly assigned for reasons unconnected to the welfare- to-work program's effects. About 30 percent of the sample in Oklahoma City were denied cash assistance shortly after being randomly assigned. Second, past research has shown that welfare-to-work programs work differently for recent applicants, who tend to be less disadvantaged, than for individuals who were already receiving AFDC.   Issues for Estimating Impacts in Riverside (see also: technical memo on estimating impacts)  The Riverside design has implications for calculating LFA impacts. The outcomes and impacts for sample members in the other six sites are unweighted. In Riverside, however, outcomes are weighted averages of the outcomes for both LFAs found to be in need and those found not to be in need of basic education at baseline. This weighting scheme compensates for the overrepresentation of those determined not to need basic education among the LFA and LFA-control groups.  Under the Riverside program design, impacts cannot be correctly calculated in an unweighted regression model (that is, one that includes LFAs, HCDs, and controls and counts all observations with equal weight). Instead, the full sample LFA impact is calculated as (Wneed * BLFAneed) + (Wnot * BLFAnot). In this equation, BLFAneed represents the impact for the "in need" LFAs and BLFAnot the impact for the "not in need" LFAs. Wneed, the weight for the "in need" sample, equals the fraction of LFAs, HCDs, and controls who were classified by program staff as in need of basic education at baseline, and Wnot, the weight for the "not in need" sample, equals 1 - Wneed.  The Riverside LFA full sample impacts are generated in a regression that includes all Riverside sample members, whereas the HCD full sample impacts are estimated in a regression that includes only sample members determined to need basic education.    Issues for Estimating Impacts in Portland (see also: technical memo on estimating impacts)  The full impact sample in Portland includes  3,529 program group members:  63.6 percent  2,018 control group members:  36.4 percent  Portland initially randomly assigned half of the sample to the program group and half to the control group.  On September 1, 1993, Portland changed the random assignment ratio to 75 percent program group and 25 percent control group. Researchers should account for this change when estimating outcomes and impacts, either by  1) Weighting the sample to even out the proportions of program group members and    control group members before and after September 1, 1993  or  2) Control for the difference in random assignment ratios when running impact    regressions or similar procedures.  MDRC used method (2) by including a dummy variable: PORTCOH2=1 if randomly assigned after the change in random assignment ratio.    SITE            RESEARCH GROUPS               DUMMY VARIABLE NAMES  Atlanta         LFA, HCD, Control             J, B, C2 Grand Rapids    LFA, HCD, Control             J, B, C2 Riverside       LFA, HCD, Control             J, B, C2  Columbus        Integrated, Traditional,      I, T, C2                 Control  Detroit         Program, Control              P, C2 Oklahoma City   Program, Control              P, C2 Portland        Program, Control              P, C2