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Early ChildhoodHuman capitalPositive

Perry Preschool Project

Ypsilanti Public Schools / High/Scope Educational Research Foundation · Ypsilanti, Michigan, USA · 1962

Summary

The Perry Preschool Project is the most influential early childhood intervention study in existence. Followed for over 40 years, children randomly assigned to receive two years of high-quality preschool outperformed controls on every major life outcome measured: education, employment, income, and criminal justice. The benefit-cost analysis—$7 returned for every $1 invested—became the standard argument for early childhood investment. The study's longevity and breadth of outcomes make it uniquely persuasive as a policy argument.

Research question

"Does high-quality preschool education for disadvantaged children produce lasting benefits into adulthood?"

Methodology

Intervention

Daily classroom sessions + weekly home visits for 2–3 year-old children from low-income African American families; high-quality active learning curriculum

Assignment

Randomized controlled trial (child)

Sample size

123 children (58 treatment, 65 control), followed to age 40+

Primary outcome

Educational attainment, employment, earnings, criminal justice involvement at multiple adult follow-ups

Effect estimate

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

Decision

Foundational evidence for Head Start expansion and preschool investment nationally; cited in virtually every early childhood policy debate

Result

Positive

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

Evidence strength

Strong

Randomized controlled trial with large sample.

Replication status

Partially replicated

Institution

Ypsilanti Public Schools / High/Scope Educational Research Foundation

Location

Ypsilanti, Michigan, USA

Year

1962

Policy area

Early Childhood

Mechanism

Human capital

Other trials of this mechanism

Cite this entry

Ypsilanti Public Schools / High/Scope Educational Research Foundation. (1962). Perry Preschool Project. The Experiment Society Registry. Retrieved from https://www.experimentsociety.org/registry/perry-preschool-project (primary report: https://highscope.org/perry-preschool-project/)

Citation network

Cited by 4 other entries in the registry

Cross-references

Adjacent experiments — same domain, parallel pilots, or alternative mechanisms.

Related experiments

Seattle, WA, USA · 2017

Seattle Preschool Program RCT

Positive

England, United Kingdom · 2010

UK Sure Start Local Programmes

Positive

Boston, Massachusetts, USA · 2009

Boston Public Pre-K Program

Positive

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