Evaluating Public Programs with Close Substitutes: The Case of Head Start
Kline, P., & Walters, C. R. · 2016
grade Bquasi-experimentindependentreplicatednumbers spot-checked
Sample
4,667 (HSIS reanalysis)
Population
HSIS sample, decomposed by what the control group actually did.
Design
Decomposes the LATE into sub-LATEs by counterfactual care mode. CAVEAT: the partial first stage for the centre-substitution margin is weak (F=1.8).
Key findings
The most important reframing in the Head Start literature: Head Start beats staying home (~+0.37 SD) but is statistically indistinguishable from the other preschools it displaces. As alternative childcare has become near-universal, the measurable effect of *adding* Head Start has shrunk accordingly — much of the apparent 'fadeout' at scale is really a counterfactual problem.
Counterfactual
THE POINT OF THE PAPER: without an offer, 55% home care, 31.5% other centre, 13.6% Head Start anyway; 34% of compliers came from competing, mostly publicly funded preschools.
Genetic confound
Experimental base; the confound at issue is the counterfactual, not genetics.
Replication notes
Independently corroborated by Weiland et al. (2020): where controls already attend centre-based care, measured effects go to zero on academic outcomes.
DOI / URL
10.1093/qje/qjw027
Effects
| Outcome | Metric | Value | Measure | Timing | Vs | Horizon | Class |
|---|---|---|---|---|---|---|---|
| Head Start vs HOME care (sub-LATE) | SD | ~+0.37, stable across specifications | standardized | end-of-treatment | business-as-usual | end-of-treatment | domain-skill |
| Head Start vs OTHER CENTRE-BASED preschool (sub-LATE) | SD | never significantly different from ZERO; slightly negative in places (weak first stage, F=1.8) | standardized | end-of-treatment | active-alternative | end-of-treatment | domain-skill |
| Marginal value of public funds | MVPF | 1.10 ignoring substitute-program savings; higher once they are counted | unknown | adult | unclear | adulthood | attainment |
Cited by
- Preschool at scale — Head Start, state pre-K, and what universal provision deliversmixedconf: highgc: low