How Effective Are Different Welfare-to-Work Approaches? Five-Year Adult and Child Impacts for Eleven Programs. Random Assignment Periods and Procedures


In each site, sample members were randomly assigned over a period of approximately two years. Random assignment began in June 1991 in Riverside, California, and ended in December 1994 in Portland, Oregon (see Table 2.2). Thus, the results presented in this report cover the calendar period from June 1991 (the month of the first Riverside sample member's entry into the study) to December 1999 (the last month of the follow-up period for the last sample member in Portland to be randomly assigned). Throughout the report, the five years of the evaluation's follow-up period are labeled year 1, year 2, and so on. These labels refer not to calendar years but to years after random assignment; for example, year 1 refers to the first year after sample members were randomly assigned, regardless of whether year 1 began in 1991 or 1994 for individual sample members.

Table 2.2
Overview of Report Sample Sizes, by Site and Research Group

Site and Program

Full Impact Sample Five-Year Client Survey Sample Two-Year and Five-Year Client Survey Respondents Five-Year Child Outcomes Study Sample Five-Year Teacher Survey Sample


Random assignment period 01/92-06/93 03/92-06/93 03/92-06/93 03/92-06/93 03/92-06/93
Labor Force Attachment 1,441 519 491 289 184
Human Capital Development 1,495 594 565 367 226
Control 1,497 552 527 311 193
Full sample 4,433 1,665 1,583 967 603

Grand Rapids

Random assignment period 09/91-01/94 03/92-01/94 03/92-01/94 03/92-01/94 03/92-01/94
Labor Force Attachment 1,557 535 506 214 144
Human Capital Development 1,542 547 511 196 120
Control 1,455 562 537 214 144
Full sample 4,554 1,644 1,554 624 408


Random assignment period 06/91-06/93 09/91-05/93 09/91-05/93 09/91-05/93 09/91-05/93
Labor Force Attachment 3,384 499 424 185 108
Human Capital Development 1,596 376 323 208 131
Control 3,342 720 648 348 222
Full sample 8,322 1,595 1,395 741 461


Random assignment period 02/93-12/94 03/93-02/94 03/93-02/94    
Program 3,529 281 238    
Control 499 223 204    
Full sample 4,028 504 442    


Random assignment period 09/92-07/94        
Integrated 2,513        
Traditional 2,570        
Control 2,159        
Full sample 7,242        


Random assignment period 05/92-06/94        
Program 2,226        
Control 2,233        
Full sample 4,459        

Oklahoma City

Random assignment period 09/91-05/93        
Program 4,309        
Control 4,368        
Full sampleV 8,677        
Full sample size 41,715 5,408 4,974 2,332 1,472
SOURCE:  MDRC-created database.

The differences in the random assignment procedures used in different sites affected the composition of the site samples and, thus, the comparability of the results for different sites and programs.(6) In five of the seven sites, welfare applicants and recipients who were required to participate in a welfare-to-work program (because they met certain demographic criteria: for instance, had no children below the minimum age set by the program) were randomly assigned while attending a program orientation at their local employment and training office. In Columbus and Oklahoma City, in contrast, people were randomly assigned at their local income maintenance office before being assigned to an orientation.

Not everyone assigned to participate in a welfare-to-work program actually attends an orientation. Reasons for not attending include leaving welfare shortly after being referred to the program, having one's welfare application denied, or simply failing to show up.(7) As a result, the people who attend a program orientation may not be representative of everyone in their locale who is required to participate in a welfare-to-work program. For example, when the waiting list for orientation "slots" is long, the people who find jobs and exit welfare before being randomly assigned are likely to be more employable, on average, than people who do not. As a result, those who enroll in the program are disproportionately likely to be "disadvantaged." Data on how many people who were required to attend an orientation actually did so are available for three sites (Riverside, Grand Rapids, and Columbus). About 66 percent in the Riverside, Grand Rapids, and Columbus Traditional programs and about 83 percent in the Columbus Integrated program attended an orientation.(8) Because outcomes in this report are reported as averages for all sample members in a group  including, in Columbus, those who did not ultimately attend an orientation  the relative effects of the Columbus Integrated and Columbus Traditional programs on sample members' participation and subsequent employment, earnings, and welfare outcomes reflect not only differences in case management strategies but in the capacity to enroll people.

The Oklahoma City results should be interpreted with the following in mind: Oklahoma City, unlike the other sites, randomly assigned only welfare applicants (including those whose application for assistance was not yet approved) to the research groups.(9) Moreover, about 30 percent of sample members in Oklahoma City were denied cash welfare assistance shortly after being randomly assigned.(10) Therefore, the impacts for the Oklahoma City program are based on a sample that included a larger proportion than in the other sites of people who never received a welfare payment after random assignment for reasons unrelated to the program. In addition, past research has shown that welfare-to-work programs have different effects on welfare applicants than on recipients, most likely because recipients tend to be more disadvantaged than applicants.(11)