Microsoft Word Heckman final 2007-03-22c jsb doc

 

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The Perry Preschool Program is the flagship intervention. Children are followed through 

age 40, with data collected annually from ages 3-11, and again at ages 14, 15, 19, 27 and 40.

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The boost in IQ faded by the time the children were in second grade (see figure 14a), but the 

program had substantial effects on educational achievement. Test scores for the treatment group 

were consistently and significantly higher through age 14, and as were literacy scores at 19 and 

27. Participants had higher grades and were more likely to graduate from high school. 

Substantially less time was spent in special education or in repeating grades, and high school 

graduation rates of participants improved (figure 14b).  

Participants were more likely to be employed, to earn more (figure 14c), and they were 

less dependent on welfare.

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 There was substantially less crime among participants (figure 

14d)—both in terms of incidence and severity, a recurrent finding of early intervention programs 

(recall the evidence summarized in table 5). However, there was no significant difference in 

grade retention by age 27 between the two groups. Teenage pregnancy was lower, and marriage 

rates were higher by age 27 for program participants. 

The Abecedarian program appears to have had an effect on IQ, but it is concentrated 

primarily among girls.

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  Figure 15a shows the overall IQ gap between treatments and controls. It 

is persistent over ages. The Abecedarian program intervenes in the very early years, and it is 

known that IQ is malleable when children are very young (see e.g., Armor; and the references in 

Cunha and Heckman, 2007). This message is reinforced by the fact that the IQ boost was not 

found among children who only experienced the later intervention. Comparable effects are found 

for reading (figure 15b) and math achievement scores (figure 15c). The test score effects persist 

through age 21, which is the last age analyzed. 

Figure 15d shows that there were substantial academic benefits. Treatment group 

members participated less in remedial special education at age 15 and repeated fewer grades at all 

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ages. High school graduation and four-year college participation rates were high. Participants 

were less likely to smoke and had better jobs (see figure 15e). 

Table 7 presents estimated costs and benefits of the Perry and Chicago programs with 

benefits discounted at a 3% rate. All figures are in 2004 dollars. The benefits vary among 

programs.

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  Perry produced some gain to parents in terms of reduced child care costs, and 

earnings gains for participants were substantial. The K-12 benefit arises from the increment in 

student quality and is a reduction in special education costs. This benefit is substantial across all 

programs. The college/adult category represents the extra tuition paid by students who go to 

college. Crime represents the reduction in direct costs (incarceration and criminal justice system) 

as well as damage done to victims. This excludes transfers. Welfare effects are modest. Future 

Generation (FG) Earnings represents the improvement in the earnings of the children of the 

program participants. Smoking and health benefits were not measured in the Perry and Chicago 

data. For Abecedarian, there were substantial effects, including major differences in smoking 

rates. CPC documents a decline in child abuse and the costs of treating abused children. The costs 

of Perry are substantial but per year are about the average cost of expenditure on public school 

students. CPC per year costs about $6,796 for the preschool and $3,428 for the school-age 

component (in 2004 dollars). The reported benefit-cost ratios are substantial: 9 to 1 for Perry; 8 to 

1 for Chicago CPC. Rolnick and Grunewald claim that the annual rate of return for Perry is 4% 

for participants and 12% for society at large, for a total of 16%. 

Much more research is needed on Perry, CPC, and a wide variety of other early childhood 

program results.

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  Results from these programs need to be put on a common footing to 

understand better the differences in samples, treatments, and effects.

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  A much more careful 

analysis of the effects of scaling up the model programs to the target population, and its effects 

on costs, has to be undertaken before these estimates can be considered definitive. 

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The gain from the pilot programs is a lower bound on the potential benefit of intervening 

in the early years: although the costs are well established, many of the benefits cannot be 

precisely monetized. For instance, we do not yet have a full accounting of how the children of the 

participants will respond to the intervention, and neglecting this likely understates its effect. 

Extrapolating from old, small, and local programs to large, national ones in the future is 

precarious business—a fact often neglected in the early childhood literature. The benefits of these 

interventions appear to be sufficiently large that the actual or potential program may remain cost-

effective even after a large reduction in its efficacy. 

 

The Case for Early Intervention 

Without claiming to offer a monolithic explanation for the origins of the major social 

problems discussed in this paper, we nonetheless point out the important role of disadvantaged 

families in producing less educated and less motivated persons and in producing persons more 

prone to participate in crime. A large literature establishes that children from disadvantaged 

homes are less educated and more likely to participate in social pathologies, including crime. In 

the past forty years or so, the American family has come under stress. Relatively more American 

children are being raised in the adverse environments that produce less educated and less skilled 

individuals and persons more likely to commit crime and participate in socially deviant behavior. 

American society has traditionally appealed to the schools to remedy what failed families 

produce. Current policies such as the No Child Left Behind Act are premised on using schools to 

remedy the consequences of disadvantaged families. Schools can only work with what families 

give them. Successful schools are those that teach children from functioning families. 

In addition, the current emphasis in American schools is on test scores, and tests ignore 

crucial noncognitive components of motivation, persistence and self-control that successful 

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