Name	Objective	Study Design	Setting and Participants	Effect on Intermediate Socioeconomic Outcomes
Early life and education (n = 11)
Alternative Schools Demonstration Program 63	To assess the effect of alternative high schools on dropout rates	Two‐arm RCT: (1) admission to an alternative high school sponsored by the demonstration; (2) control group (not admitted)	In 7 urban school districts (Los Angeles, CA; Stockton, CA; Denver, CO; Wichita, KS; Cincinnati, OH; Newark, NJ; Detroit, MI)     N = 924	The effect of the program varied depending on the study sites; overall, the program yielded mixed findings, with positive effects on dropouts in certain sites but no effect on employment.
Carolina Abecedarian Project 46 , 47 , 48 , 49 , 50 , 51	To assess whether intensive early childhood education could improve school readiness	Two‐arm RCT: (1) intensive educational childcare program from infancy to kindergarten entry; (2) control group (no intervention)	Children at risk of developmental delays or academic failure based on households scores on High Risk Index in North Carolina     N = 52 to 148 depending on the outcome and study	Children assigned to the program had large IQ score improvements by age 3 years, higher reading and math abilities by age 15 years, lower rates of teen pregnancy and depression, and greater likelihood of attending college at age 21 years.
Head Start 55 , 56	To determine the impact of Head Start on children's school readiness and parental practices that support children's development	Two‐arm RCT: (1) Head Start program services; (2) control group (not in Head Start; could enroll in other early childhood programs or services)	3‐ and 4‐year‐old eligible children in 383 randomly selected Head Start centers.     N = 2,259	Children in the program group had a better preschool experience and improved school readiness on a number of dimensions. The program had minimal impact on cognitive and socio‐emotional outcomes of participating children.
High/Scope Perry Preschool Program 52	To evaluate whether an intensive preschool program improved long‐term outcomes	Two‐arm RCT: (1) intensive 2‐year program of 2.5 hours of interactive academic instruction with 1.5‐hour weekly home visits; (2) control group (no intervention)	Children were recruited from low‐income, predominantly African American neighborhoods in Ypsilanti, MI     N = 123	Children in the treatment group were more likely to complete more schooling, have a stable family environment, and have higher earnings in adulthood.
Infant Health and Development Program 53 , 54	To assess the efficacy of early education on a range of parental and child outcomes	Two‐arm RCT: (1) home visits from birth of a low‐birth weight, premature child to the child's’ third birthday, and center‐based child development programming in the second and third years of life; (2) control group receiving pediatric follow‐up only	Low‐birth weight, premature infants (birthweight <2500g and a gestational age <37 weeks) born in eight participating cities (Little Rock, AR; Bronx, NY; Cambridge, MA; Miami, FL; Philadelphia, PA; Dallas, TX; Seattle, WA; New Haven, CT)     N = 875	Mothers in the intervention group were employed more months and returned to work sooner after births of their children. Children in the intervention group reported higher scores in math and reading.
Quantum Opportunities Project 57	To evaluate whether a youth development demonstration can provide educational benefits	Two‐arm RCT: (1) ≤750 hours of education, development, and service per year from ninth grade through high school; (2) control group (no intervention)	In‐school youth or youth who had dropped out in San Antonio, TX; Philadelphia, PA; Milwaukee, WI; Saginaw, MI; Oklahoma City, OK     N = 250	Those enrolled in the program were more likely to graduate from high school, enroll in college, and receive awards, and less likely to have children and drop out of school.
Quantum Opportunity Demonstration 58	To assess the effect of offering intensive and comprehensive services on the high school graduate and postsecondary enrollment of at‐risk youth	Two‐arm RCT: (1) Five years of after‐school program providing case management and mentoring, supplemental education, developmental activities, community service activities, supportive services, and financial incentives; (2) control group (no intervention)	Youth with low grades entering high schools with high dropout rates in Cleveland, OH; Fort Worth, TX; Houston, TX; Memphis, TN; Washington DC, Philadelphia, PA; Yakima, WA     N = 1,069	The program did not impact high school graduation and postsecondary enrolment rates.
National Job Corps 59	To assess the effect of a youth training program on employment and related outcomes	Two‐arm RCT: (1) enrollment in Job Corps, which provided extensive education, training and other services; (2) control group, which could join other programs available in their communities	Youths ages 16 to 24 years from disadvantaged households (defined as living in a household that receives welfare or has income below the poverty level)     N = 11,313	Participants in the intervention group had higher education attainment, higher employment, and higher earnings overall.
Project Student Teacher Achievement Ratio 61 , 62	To assess the long‐term effect of receiving instruction in small classes, regular‐size classes, or regular‐size classes with a certified teacher's aide	Three‐arm RCT: (1) small class (13‐17 students); (2) regular‐size class (22‐25 students); (3) regular‐size class (22‐25 students) with a certified teacher's aide	Children based in 79 Tennessee schools selected based on their size and willingness to participate in the study     N = 11,601	Children assigned to small classes achieved higher test scores, had higher high school graduation rates, and were more likely to take college entrance examinations.
School Dropout Demonstration Assistance Program 60	To assess the effect of dropout‐prevention programs across the United States	Two‐arm RCT: (1) program funded by US Department of Education; (2) control group (not enrolled in the program)	Children in middle schools in Albuquerque, NM; Atlanta, GA; Flint, MI; Long Beach, CA; Newark, NJ; Rockford, IL; Sweetwater, IN.     N = 334	Only children enrolled in high‐intensity programs had higher grades and were less likely to drop out.
YouthBuild 64	To assess the effect of an intervention providing construction‐related or other vocational training, educational services, counseling, and leadership development opportunities on employment outcomes	Two‐arm RCT: (1) YouthBuild program; (2) control group (not enrolled)	Low‐income youths aged 16‐24 years who did not complete high school in 250 participating organization nationwide     N = 3,929	Participants in the program group had higher participation in education and training, small increases in wages and earnings, and higher civic engagement.
Income maintenance and supplementation (n = 7)
Family Rewards 2.066	To assess the effect of a modified version of the Family Rewards model supplemented by staff guidance	Two‐arm RCT: (1) Family Rewards 2.0 conditional cash transfer, with conditions in the domains of health care, education, and employment; (2) control group (no intervention)	Low‐income households in the Bronx, NY, and Memphis, TN     N = 2,400	Family Rewards 2.0 increased income and reduced poverty but also led to a reduction in employment covered by the unemployment insurance system, driven by the Memphis site.
Gary Experiment 70	To test the effects of a negative income tax, consisting of an income guarantee accompanied by a tax rate on other income	Five‐arm RCT: (1) 4 combinations of guarantees and tax rates; (2) control group	African American families with at least one child under the age of 18 years living in Gary, IN     N = 404	The program was associated with a reduction in employment rates of males and single females, and an increased likelihood that teenager continued school.
New Jersey and Pennsylvania Negative Income Experiment 68	To test the effects of a negative income tax, consisting of an income guarantee accompanied by a tax rate on other income	Nine‐arm RCT: (1) 8 combinations of guarantees and tax rates; (2) control group	Low‐income households with 1 nondisabled member between the ages of 18 and 59 years and ≥1 other member living in Trenton, NJ; Jersey City, NJ; Paterson, NJ; or Scranton, PA     N = 1,357	The program was associated with an increase in parental unemployment and increased teenage high school graduation rates.
Opportunity NYC–Family Rewards 65	To test the effect of a conditional cash transfer program in the US	Two‐arm RCT: (1) Family Rewards conditional cash transfer, with conditions in the domains of health care, education, and employment; (2) control group (no intervention)	Low‐income households in New York, NY     N = 4,749	Family Rewards led to a significant increase in household income and a reduction in poverty and material hardship for the duration of the program but was not associated with an increase in parental employment.
Opportunity NYC–Work Rewards 67	To test two strategies to increase employment and earnings of families receiving housing vouchers: the Family Self‐Sufficiency program (FSS), which offers case management, and an enhanced version of this program (FSS + incentives), which includes cash incentives to encourage sustained full‐time employment	Two‐arm RCT: (1) FSS alone; (2) FSS plus special work incentives	Housing voucher recipients based in New York, NY     N = 1,603	FSS and FSS + incentives did not increase employment or earnings overall and did not reduce receipt of housing assistance, poverty, or incidence of material hardship.
Rural Income Maintenance Experiment 69	To test the effects of a negative income tax, consisting of an income guarantee accompanied by a tax rate on other income	Six‐arm RCT: (1) 5 combinations of guarantees and tax rates; (2) control group	Rural low‐income households, with a nondisabled man between the ages of 18 and 59 years living in Duplin (NC), Pocahontas (WV) or Calhoun (IA) counties     N = 554	The program was associated with reduced family income and lower employment rates.
Seattle‐Denver Income Maintenance Experiment 71 , 72 , 73	To test the effect of both a negative income tax and subsidized vocational counseling and training	Three‐arm RCT: (1) financial treatment at different levels of income guarantee and tax rate; (2) counseling/training treatment; (3) control group	Families meeting the following criteria: (1) either married or single with ≥1 dependent child under 18 years of age; (2) earning either <$9,000 or <$11,000 per year in 1971 dollars; (3) included a nondisabled head of household, aged 18 to 58 years     N = 2,280 to 7,500 depending on the study	The programs were associated with longer unemployment spells, decreased earnings, and increased debt.
Employment and welfare‐to‐work (n = 13)
Connecticut Jobs First Program 85	To evaluate the effects of a 21‐month limit on welfare benefits coupled with an employment mandate and incentives for finding and keeping a job	Two‐arm RCT: (1) benefit cap of 21 months of welfare coverage, employment mandate, childcare assistance, earned income disregard, and 2 years of Medicaid eligibility after leaving welfare; (2) control group receiving AFDC benefits	Low‐income families receiving AFDC in Connecticut     N = 4,803	Participation in the program was associated with significant employment and income benefits.
Florida Family Transition Program 32	To evaluate the effects of a 24‐ or 36‐month limit on welfare benefits coupled with enhanced employment‐related services such as education, job training, and job placement	Two‐arm RCT: (1) time limits on welfare benefits and extra job training and case management; (2) control group receiving regular benefits and no additional job counseling	New AFDC applicants and existing AFDC recipients in Escambia and Alachua Counties, FL, ages 18‐60 years, not in school, not working >30 hours per week, not disabled or caretakers for a disabled person, and not caring for a child age <6 months     N = 3,324	Participants in the intervention group were more likely to find work, but their earnings did not tend to be greater than the total income from all sources received by the control group. Half of the intervention group remained unemployed during the program and reported relying on support from friends, family, and other programs such as food stamps.
GAIN 77	To assess the impact of a welfare‐to‐work program aiming to reduce dependence and increase self‐sufficiency by providing comprehensive support services	Two‐arm RCT: (1) basic education and training; also, job search assistance for those who did not have a high school diploma or a GED, or job search assistance for those who were not screened as needing more basic education; (2) control group with access to other community services	Low‐income families eligible to AFDC in 6 California counties     N = 3,314	Participation in the program increased parental earnings and reduced welfare payments.
Iowa Family Investment Program 86	To assess the impact of Iowa's new welfare‐to‐work program	Two‐arm RCT: (1) comprehensive package of incentives to encourage self‐sufficiency, including an earning disregard, participation in employment and training programs, and no restrictions on eligibility for 2‐parent families; (2) control group receiving AFDC	Low‐income families eligible for welfare benefits in Iowa     N = 1,866	Participation in the program was associated with increases in employment, earnings, and incidence of domestic abuse.
JOBS I Program 79 , 80	To evaluate the impact of an employment intervention on persons with different levels of risk factors for depression	Two‐arm RCT: (1) eight 3‐hour group job training sessions over a 2‐week period; (2) control group (no intervention)	Unemployed people recruited from Michigan Employment Security Commission offices     N = 928 to 1,122 depending on the study	The intervention primarily increased employment among participants at high‐risk of depression.
JOBS II Program 81	To evaluate the impact of an employment intervention on persons with different levels of risk factors for depression, with the addition of a screening tool to identify those at high‐risk of losing jobs	Two‐arm RCT: (1) five 3‐hour group job training sessions over a 1‐week period; (2) control group (no intervention)	Unemployed people recruited from Michigan Employment Security Commission offices     N = 1,801	The intervention primarily increased employment among participants at high‐risk of depression.
Mental Health Treatment Study 75	To test whether supported employment and mental health treatments improve vocational and mental health recovery for people with psychiatric impairments	Two‐arm RCT: (1) multifaceted intervention combining team‐supported employment, systematic medication management, and other behavioral services; (2) control group receiving usual services	SSDI beneficiary with a primary diagnosis of schizophrenia or mood disorder, interested in gaining employment, age 18‐55 years, and residing within 30 miles of one of the 23 study sites     N = 2,238	The intervention was effective in assisting return to work and improving mental health and quality of life.
National Evaluation of Welfare‐to‐Work Strategies 77	To assess the impact of labor‐force attachment vs human capital development welfare‐to‐work programs on welfare recipients and their children	Two‐arm RCT: (1) labor‐force attachment or human capital development program; (2) control group (no intervention)	Low‐income families eligible for AFDC in Atlanta, GA; Grand Rapids, MI; Riverside, CA; and Portland, OR.     N = 2,938	Participation in employment‐focused programs was associated with increases in employment and earnings and decreases in welfare receipt.
National Supported Work Demonstration 76	To test the effect of employment and training programs on assisting hard‐to‐employ persons	Two‐arm RCT: (1) work experience under conditions of gradually increasing demands, close supervision, and work in association with a crew of peers; (2) control group (no intervention)	Individuals with severe obstacles to obtaining employment and little recent work experience—ie, women receiving AFDC for many years, people with substance abuse histories, people with criminal records, and young adults who had dropped out of school—in 15 sites across the United States     N = 6,616	The program was most effective in preparing women receiving AFDC and people with substance abuse histories for employment; it had no effects on those with criminal histories or the youth group.
New Hope 83	To assess the impact of providing full‐time workers with benefits and those unable to find full‐time employment with support to find a job and referral to wage‐paying community service job	Two‐arm RCT: (1) earning supplement, health insurance, childcare assistance, and job access under a 30‐hour work requirement; (2) control group (no intervention)	Low‐income individuals age ≥18 years, willing and able to work full time, and living in a targeted Milwaukee, WI, neighbourhood     N = 691	Participants were more likely to work, had higher incomes, and made more use of center‐based childcare. Children from participating families had higher academic performance and test scores.
New Jersey's Family Development Program 87	To assess the impact of New Jersey's new welfare‐to‐work program	Two‐arm RCT: (1) family cap, earned‐income disregard, no marriage penalty, increased benefits for two‐parent households, extended Medicaid eligibility, employment support, and sanctions for noncompliance; (2) control group receiving AFDC benefits	Low‐income families eligible for AFDC in New Jersey     N = 1,232	The program reduced welfare dependency among participants, but its effects on employment and earnings are unclear.
Teenage Parent Welfare Demonstration 82	To test the impact of a welfare‐to‐work program for teenage parents coupled with mandatory school and work requirements, and support services	Two‐arm RCT: (1) mandatory school and work requirements enforced by financial sanctions; support services such as case management, parenting workshops, childcare assistance, and education and training opportunities; (2) control group receiving regular services	Teenage parents eligible for welfare in Chicago, IL, or New Jersey     N = 3,867	The program increased attendance at school and job training programs and modestly increased employment rates.
Working Towards Wellness 84	To evaluate the impact on employment and earnings of a care management program providing support for parents with depression who face barriers to employment	Two‐arm RCT: (1) telephonic care management program, including education about depression, treatment, and monitoring of treatment adherence; (2) control group (no intervention)	Parents receiving Medicaid with symptoms of depression in Rhode Island     N = 1,866	The program had no effect on employment.
Housing and neighbourhood (n = 4)
Effects of Housing Vouchers on Welfare Families Study 96	To measure the effects of vouchers on the well‐being of low‐income families eligible for or receiving TANF	Two‐arm RCT: (1) experimental group receiving housing vouchers; (2) control group not receiving the housing voucher but remaining on the public housing authority's waiting list for regular assistance	Families eligible for Housing Choice Vouchers and current/former TANF recipients in Atlanta, GA; Augusta, GA; Fresno, CA; Houston, TX; Los Angeles, CA; and Spokane, WA     N = 2,463	Vouchers reduced homelessness, crowding, household size, and incidence of living with family and friends. They also increased housing mobility and resulted in a small improvement in housing quality.
Housing Opportunities for People with AIDS 97	To assess the effects of rental assistance on the health and risk behavior of homeless and unstably housed people living with HIV/AIDS	Two‐arm RCT: (1) experimental group receiving immediate rental assistance with case management; (2) control group receiving customary housing services with case management	Adults age ≥18 years who were HIV‐seropositive, homeless or at severe risk of homelessness, and with income <50% of median area income in Baltimore, MD; Chicago, IL; and Los Angeles, CA     N = 630	Participation in the program was associated with improvements in housing status.
HUD‐VA Supported Housing Program 88 , 89	To evaluate the effects of providing integrated clinical and housing services to homeless veterans with psychiatric and/or substance abuse disorders	Three‐arm RCT: (1) HUD‐VA Supported Housing Program treatment group; (2) intensive case management without special access to Section 8 vouchers treatment group; (3) control group receiving standard VA homeless services	Veterans being treated at 19 participating VA medical centers located across the country. Veterans were eligible if they had been homeless for ≥1 month and had a diagnosis of a major psychiatric disorder and/or an alcohol or drug abuse disorder     N = 272 to 370 depending on study	Participation in the program was associated with an increase in days housed and a reduction in homelessness.
Moving to Opportunity 90 , 91 , 92 , 93 , 94 , 95	To evaluate the effects of providing housing vouchers to families living in public housing, with and without neighborhood restrictions	Three‐arm RCT: (1) experimental group, receiving housing vouchers for use in low‐poverty neighborhoods; (2) Section 8 treatment group receiving housing vouchers without neighborhood restrictions; (3) control group (no vouchers but eligible for public housing)	Children age ≤20 years from families living in high‐poverty neighborhoods in Baltimore, MD; Boston, MA; Chicago, IL; Los Angeles, CA; and New York, NY     N = 369 to 3,946 depending on study	Participation in the experimental group was associated with a lower likelihood of living in a high‐poverty neighborhood, better housing quality, feeling safer in neighborhoods, and residing in less racially segregated neighborhoods.
Health insurance (n = 3)
Accelerated Benefits Demonstration 105 , 106	To test whether early access to health care and related services improves outcomes for new SSDI beneficiaries	Three‐arm RCT: (1) AB group, which had access to health care benefits designed for the demonstration; (2) AB Plus group, which had access to the same health care benefits and voluntary services delivered by telephone to help navigate the health care system and return to work; (3) control group (no intervention)	New SSDI beneficiaries without health insurance who had ≥15 months until eligibility for Medicare; were aged 18‐54 years; lived in one of the 53 metropolitan statistical areas with the highest number of new SSDI beneficiaries     N = 1,226 or 1,531 depending on study	AB Plus services encouraged job seeking.
Oregon Health Insurance Experiment 101 , 102 , 103 , 104	To assess the effect of expanding Medicaid coverage of low‐income adults	Two‐arm RCT: (1) Medicaid coverage; (2) control group (no intervention)	Low‐income Oregon residents, aged 19‐64 years, ineligible for other public health insurance and uninsured for the past six months     N = 4,166 to 74,922 depending on study	Medicaid coverage nearly eliminated catastrophic out‐of‐pocket medical expenditures.
RAND‐Health Insurance Experiment 98 – 100	To assess whether free medical care leads to better health than cost‐sharing insurance plans	Two‐arm RCT: (1) free medical care; (2) control group required to pay a share of their medical bills	Low‐income individuals aged 14‐61 years living in Seattle, WA; Dayton, OH; Fitchburg or Franklin County, MA; and Charleston or Georgetown County, SC.     N = 1,844 to 6,622 depending on study	Cost sharing was associated with a reduction in medical care, in particular among poorest respondents.

Abbreviations: AFDC, Aid to Families with Dependent Children; FSS, Family Self‐Sufficiency; GED, General Education Development; HUD, US Department of Housing and Urban Development; RCT, randomized controlled trial; SSDI, Social Security Disability Insurance; TANF, Temporary Assistance for Needy Families; VA, US Department of Veterans Affairs.