Build skills
Human capital
Human-capital interventions invest directly in a person's skills, education, or capability — job training, early-childhood schooling, college coaching, financial literacy. The mechanism is durable: the gain is internal to the person and persists after the program ends.
32
Experiments
8
Policy areas
1962–2018
Year span
28 / 32
Positive
When it works
When the skill gap is the actual binding constraint on the outcome, when the training is matched to actual labor-market or life demand, and when the program is intensive enough to move the underlying capability. Effects often take years to fully appear.
Watch out for
Most human-capital interventions are expensive per participant and depend critically on instructor quality. The variance across implementations of the 'same' program is often larger than the variance between different programs. Replicate the implementation, not just the design.
Human capital across policy areas
Education· 9 experiments
- Positive
Year Up Young Adult Job Training Program
Year Up / Social Policy Research Associates / Harvard · United States · 2018
Effect: Quarterly earnings: +$1,000/quarter (+30%) at 3-year follow-up; annual earnings advantage: ~$4,500; employment rate: +11 pp; effect sustained through year 5 in extended follow-up
- Positive
Chicago STAR Scholarship — Dual Enrollment
City Colleges of Chicago / University of Chicago · Chicago, IL, USA · 2016
Effect: FAFSA completion: +5.4 pp; City Colleges enrollment: +3.2 pp; college persistence to year 2: +4.1 pp; effects largest for first-generation students
- Positive
Universal Free School Breakfast Program
Welsh Assembly Government · Wales, UK · 2007
Effect: +2 months additional academic progress for Key Stage 1 students
- Positive
Harlem Children's Zone — Promise Academy Charter Schools
Harvard University / Harlem Children's Zone · New York City, USA · 2004
Effect: Middle school HCZ: math scores closed Black-white achievement gap entirely (+.23 SD effect per year); English/ELA: smaller but significant gains (+.047 SD/year); elementary school: similar math gains. Key finding: lottery analysis suggested community programs outside school showed limited independent effect — it was the school that drove gains
- Mixed
National Job Corps Study
Mathematica Policy Research (Schochet, Burghardt, Glazerman) · United States (national) · 1995
Effect: At 4 years post-assignment: 12% increase in earnings ($22/week); 1.6 percentage point increase in employment; significant reduction in criminal behavior during the program years; criminal behavior effects faded after the program ended; credential attainment significantly higher in treatment group
- Mixed
Job Training Partnership Act (JTPA) National RCT
Mathematica Policy Research / US Department of Labor · United States · 1994
Effect: Adult women: +$1,500 earnings at 30 months (+12%); adult men: no statistically significant effect; out-of-school youth: negative effect during training; female youth: small positive effect
- Positive
Career Academies — MDRC Long-Term Evaluation
MDRC · Multiple US cities · 1993
Effect: Earnings at 8-year follow-up: +11% for all participants ($16,600 vs. $14,900); young men: +17% ($1,728 per year); no effect for young women; males also had higher rates of living with romantic partners and children — interpreting as more stable family formation
- Positive
Project STAR — Small Class Size
Tennessee Department of Education · Tennessee, USA · 1989
Effect: +4 percentile points in small vs. regular class; effect doubled for minority and low-income students; long-term earnings gains documented in follow-up studies
- Positive
Tennessee STAR — Student/Teacher Achievement Ratio
Tennessee Department of Education / SBER / Vanderbilt / Harvard · Tennessee, USA · 1985
Effect: Test scores: small-class students scored 4–8 percentile points higher than regular-class students; effects largest for minority students (+10 pp) and low-income students (+8 pp). Persistence: test score advantage visible through 8th grade (4–5 years after returning to regular classes). Long-term: Chetty et al. (2011) found STAR students had 1.6% higher earnings in adulthood; college attendance rates 2.7 pp higher; probability of home ownership 4.6 pp higher.
Early Childhood· 7 experiments
- Positive
Seattle Preschool Program RCT
University of Washington / City of Seattle · Seattle, WA, USA · 2017
Effect: School readiness: +0.32 SD; language development: +0.28 SD; social-emotional skills: +0.19 SD; effects largest for dual-language learners and lower-income families
- Positive
UK Sure Start Local Programmes
HM Government / Institute for Fiscal Studies · England, United Kingdom · 2010
Effect: Age 11 test scores: +0.1 SD; emergency hospitalizations: −11%; obesity at age 11: −2.4 pp; special needs referrals: reduced
- Positive
Boston Public Pre-K Program
Harvard Graduate School of Education (Weiland, Yoshikawa) · Boston, Massachusetts, USA · 2009
Effect: Language composite: +0.32 SD; mathematics: +0.33 SD; executive function: +0.45 SD — among the largest pre-K effects documented in the US literature; gains more than doubled those found in typical Head Start evaluations
- Positive
Jamaica Stunting Study — Stimulation + Nutrition
University of the West Indies / World Bank · Kingston, Jamaica · 1986
Effect: Stimulation arm: +42% adult earnings compared to control; fully closed the earnings gap with non-stunted peers after 20 years; supplementation alone had no significant long-term effect
- Positive
Nurse-Family Partnership — Elmira Trial
University of Rochester / David Olds · Elmira, New York, USA · 1977
Effect: −80% verified child abuse and neglect at age 2; −56% emergency room visits; at 15-year follow-up: −48% child arrests, −59% maternal arrests, −83% convictions for low-income unmarried mothers
- Positive
The Abecedarian Project
University of North Carolina at Chapel Hill / Frank Porter Graham Child Development Institute · Chapel Hill, NC, USA · 1972
Effect: IQ at age 21: +4.4 points; college attendance by age 21: 23% vs. 6% control (+17 pp); full-time employment at age 21: 42% vs. 32%; at age 40: treatment group had significantly lower rates of cardiovascular disease risk factors (hypertension, obesity, metabolic syndrome); returns estimated at $2.50–$4 per dollar invested
- Positive
Perry Preschool Project
Ypsilanti Public Schools / High/Scope Educational Research Foundation · Ypsilanti, Michigan, USA · 1962
Effect: By age 40: treatment group had higher graduation rates (+23 pp), higher employment (+26 pp), higher median earnings (+42%), lower arrest rates (−22 pp); estimated benefit-cost ratio of 7–12:1
Public Health· 4 experiments
- Null
Workplace Wellness Programs — Illinois RCT
University of Illinois / Harvard / National Bureau of Economic Research · University of Illinois, USA · 2016
Effect: Healthcare spending: no significant difference (p>0.05 across all 38 outcomes pre-specified). Exercise: significantly higher self-reported exercise in treatment group. Weight, blood pressure, cholesterol, smoking: no significant difference. Absenteeism: no significant difference. Job performance: no significant difference. Tenure: no significant difference. The one positive finding — exercise — did not translate to any measurable health outcome.
- Mixed
Head Start Impact Study
US Department of Health and Human Services · United States (nationally representative) · 2002
Effect: Age 3 cohort: meaningful reading/literacy gains by end of program year; by 1st grade: no significant cognitive differences; 3rd grade follow-up: minimal lasting impacts; some positive health and parenting effects persisted
- Positive
IMPACT Collaborative Care for Late-Life Depression
University of Washington / RAND / multiple health systems · United States · 2002
Effect: Depression-free days: +115 days over 24 months vs. usual care; clinical response at 12 months: 45% vs. 19%; quality-adjusted life year difference: 0.26 QALYs; cost-effective at $500 per QALY gained
- Positive
IPS Supported Employment for Severe Mental Illness
Dartmouth Psychiatric Research Center / SAMHSA · Multiple US cities and international sites · 1996
Effect: Competitive employment at 18 months: 61% IPS vs. 23% standard vocational rehabilitation (original US RCT); international multi-site trial: 55% vs. 28%; meta-analysis across 11 RCTs: IPS approximately doubles competitive employment rates; no significant difference in psychiatric hospitalizations or symptoms
Public Safety· 4 experiments
- Positive
Becoming a Man (BAM) — Cognitive Behavioral Therapy
University of Chicago Crime Lab / Youth Guidance · Chicago, IL, USA · 2015
Effect: Violent crime arrests: −44% during program year; school engagement: +14%; graduation rates: +19% in 4-year follow-up
- Positive
Chicago One Summer Plus — Summer Jobs and Violence Reduction
University of Chicago Crime Lab / City of Chicago · Chicago, IL, USA · 2012
Effect: Violent crime arrests: −43% during program period; effect persisted at −13 months post-program (13 months after jobs ended); no significant effect on property crime arrests; program cost per violent crime arrest averted: approximately $1,100
- Positive
Cognitive Behavioral Therapy for Juvenile Offenders
University of Chicago Crime Lab · Chicago, IL, United States · 2012
Effect: 44% reduction in violent crime arrests; school engagement improved
- Positive
Becoming a Man (BAM) — Cognitive Behavioral Therapy for At-Risk Youth
University of Chicago Crime Lab · Chicago, IL, USA · 2009
Effect: Violent crime arrests: −44% to −50% during program year; total arrests: −30% to −35%; school engagement: significantly improved; graduation rates: +14% to +19% in follow-up. Effects on violence persisted for at least one year post-program. No significant effect on test scores.
International Development· 4 experiments
- Positive
Kenya Girls' Primary School Merit Scholarship Program
MIT Poverty Action Lab (Duflo, Dupas, Kremer) · Western Kenya · 2004
Effect: Girls in treatment schools improved test scores by 19.5 percentile points at year-end; boys in treatment schools also improved significantly (12.5 percentile points), despite being ineligible for the scholarship — indicating positive peer spillovers
- Positive
India Midday Meal Scheme
Indian Central Government / State governments · India (national, with state variation) · 2002
Effect: Enrollment: +14% in treatment states vs. untreated; attendance: +6 pp; gender gap in enrollment narrowed by ~23%; caloric intake improved for eligible children
- Positive
The Balsakhi Tutoring Program
MIT Poverty Action Lab (Banerjee, Cole, Duflo, Linden) · Vadodara and Mumbai, India · 2002
Effect: 0.14 SD improvement in Vadodara after one year; 0.28 SD in Mumbai; effects persisted two years after the program ended even for students who had moved to other schools
- Positive
Primary School Deworming — Kenya
ICS / MIT Poverty Action Lab · Western Kenya · 1998
Effect: School participation: +7.5 percentage points; cost per additional year of schooling: $3.50; long-run earnings for treated cohort: +14% at age 20
Financial Services· 2 experiments
- Positive
Year Up Job Training Evaluation
MDRC / Year Up · United States (multiple cities) · 2018
Effect: +53% earnings gain for Year Up participants; $8,000 more per year at year 3
- Positive
Financial Coaching for Low-Income Adults
Consumer Financial Protection Bureau / MDRC · United States (multiple cities) · 2015
Effect: Credit score: +19 points at 12 months; savings: +$168 median; bill timeliness: +11 percentage points