Recent legislation has affected the populations served by the Social Security Administration 's (SSA's) disability programs. The Contract with America Advancement Act of 1996 mandated that persons whose disability determination was based on drug addiction or alcoholism be removed from the Supplemental Security Income and Social Security Disability Insurance rolls. The Personal Responsibility and Work Opportunity Reconciliation Act of 1996 (later amended by the Balanced Budget Act of 1997) tightened the SSI eligibility criteria for children and converted the Aid to Families with Dependent Children program into a block grant, Temporary Assistance for Needy Families. This article describes the design of three related studies evaluating the direct and indirect effects of these policy changes on SSA's disability populations. It describes the methodological challenges of the studies and the strategies used to overcome them. It also presents early evidence from the three studies and discusses future directions.
During the past several years, the U.S. social safety net has gone through substantial changes involving an emphasis on personal responsibility and incentives, the shift of certain responsibilities to the states, and new limits on entitlements for benefits. Two pieces of recent legislation affected the Social Security Administration's (SSA's) disability programs. Section 105 of Public Law 104-121, enacted on March 29, 1996, mandated the removal of persons from the Supplemental Security Income (SSI) and Social Security Disability Insurance (DI) rolls for whom drug addiction and alcoholism (DA&A) were material to the determination of disability. It eliminated allowances on the basis of DA&A immediately and required the termination of benefits to all persons receiving benefits at the time of enactment.
The other major piece of legislation was the Personal Responsibility and Work Opportunity Reconciliation Act (PRWORA) of 1996, which was later amended by the Balanced Budget Act (BBA) of 1997. PRWORA converted the Aid to Families with Dependent Children (AFDC) program from an open-ended entitlement program into a block grant, Temporary Assistance for Needy Families (TANF), incorporating time limits on the receipt of benefits as well as strict work requirements. PRWORA also tightened child eligibility for SSI, narrowed eligibility for noncitizens, and reduced funding for food stamps. The BBA restored SSI eligibility for noncitizens receiving SSI prior to August 1996 and for legal noncitizens residing in the United States prior to August 1996 who become disabled in the future.
SSA designed three studies to assess the effects of this legislation.1 Two of the studies focused on direct effects on SSA's disabled beneficiary population, targeting drug addicts and alcoholics and SSI children. The third study focused on the indirect effects of PRWORA, particularly the replacement of AFDC with TANF, on SSA's programs. The three studies were tied together by a concern of the overall effects-direct or indirect-of the legislative changes on SSA's beneficiary populations and a host of interrelated evaluation issues.
The key methodological challenge of these evaluations is the nonexperimental nature of the evidence. The legislative pieces mandating the changes designed to affect SSA's target populations were implemented nationally, without prior demonstration projects. Nonexperimental strategies, such as comparison group designs, must therefore be used to measure the effects of interest.
Other challenges relate to the time frames. Since implementing the changes requires a certain amount of time, and outcomes are realized over a period of time after that, the information that can be made available to interested policymakers in the short run is inherently limited to descriptive data on the populations affected and to impressionistic evidence from case studies and process study analyses. …