Codebook — Perry Preschool Outcomes (Case E)
Codebook — Perry Preschool Outcomes (Case E)
What this file is. A small table of the real, published headline outcomes of the HighScope Perry Preschool Study, taken from the official age-40 report (Schweinhart, Montie, Xiang, Barnett, Belfield, and Nores, Lifetime Effects: The High/Scope Perry Preschool Study Through Age 40, HighScope Press, 2005). It is aggregate published data, not participant-level microdata — the study’s individual records are restricted-use and are not distributed here. Every percentage below is a figure reported in the official study; the whole-child counts are the integers those percentages imply given the known group sizes.
The study. From 1962 to 1967 the HighScope Educational Research Foundation (a nonprofit) ran a preschool program in Ypsilanti, Michigan, for 123 low-income children judged to be at high risk of school failure. Children were randomly assigned to a program group (n = 58) or a no-program comparison group (n = 65) and followed for decades. Because n is small and outcomes are mostly yes/no, the natural analyses are two-proportion comparisons, risk differences, and a cost-benefit calculation — all reproducible in Excel from the table below.
Columns
| Column | Meaning |
|---|---|
outcome | The measured outcome (all binary: the person either did or did not meet it). |
measure_age | Participant age at which the outcome was measured (40, or 5 for the IQ measure). |
program_pct | Percent of the program group (n = 58) meeting the outcome — as published. |
program_n | Program group size (58). |
program_count | Whole-child count implied by program_pct × 58, rounded. |
comparison_pct | Percent of the no-program group (n = 65) meeting the outcome — as published. |
comparison_n | Comparison group size (65). |
comparison_count | Whole-child count implied by comparison_pct × 65, rounded. |
source | Citation for the published figure. |
Other real published figures (not in the table)
- High school graduation, females only: 84% (program) vs. 32% (comparison). The female-subgroup denominators are not published here, so no counts are given.
- Median annual earnings at 40: $20,800 (program) vs. $15,300 (comparison).
- Cost-benefit (Schweinhart et al. 2005; constant 2000 dollars, 3% discount rate): about $16.14 returned to society per $1 invested ($244,812 in benefits on a $15,166 per-child investment); about $12.90 per $1 to the public, of which roughly 88% ($171,473) came from reduced crime. An earlier age-27 analysis reported $7.16 per $1.
- Independent reanalysis (Heckman, Moon, Pinto, Savelyev, and Yavitz 2010, Journal of Public Economics 94:114–128; NBER Working Paper 16180): an estimated 7–10% annual social rate of return, roughly $7–$12 per $1, computed with standard errors that account for small-sample and randomization issues.
Want real downloadable microdata?
Perry’s participant-level records are restricted. For a genuinely public, downloadable small-N early-childhood file, use the Carolina Abecedarian Project (ICPSR / Child and Family Data Archive, Study 4091, DOI 10.3886/ICPSR04091.v2; free account, public-use files, n ≈ 111). Its cost-benefit ratio (≈ 7.3; internal rate of return ≈ 13.7%) is reported by García, Heckman, Leaf, and Prados (2020, Journal of Political Economy; NBER 22993).