BY W. STEVEN BARNETT | The renewed debate over Head Start’s effectiveness is discouraging for anyone for whom the use of scientific evidence in policy making is paramount. On the one hand, critics assert that Head Start doesn’t work at all, much less replicate the results that small-scale intensive programs produced in research. Head Start’s defenders reply that some studies find Head Start produces results nearly as strong as those of the most vaunted intensive programs and long-term gains should be expected despite short-term fade out. Which side is correct? Neither.
Head Start critics base their claim that Head Start has little or no lasting effects on a recent large national randomized trial of the program. It is never a good idea to draw conclusions for policy based on just one study, but a recent one by the Department of Health and Human Services is the best “gold standard” study of Head Start to date. However, the study does not say what critics claim it says. The results the critics cite compare children assigned to Head Start to children assigned to a control group. Unfortunately, these results do not provide an unbiased estimate of Head Start’s effects for at least three reasons.
First, not all children followed the random assignment—some assigned to Head Start did not attend, some assigned to the control group went to Head Start–actual effects are 50 percent larger than the critics acknowledge for this reason alone. Second, control group children also attended other preschool programs pushing the underestimation even higher. Third, even though gains from Head Start are observed to diminish over time, this cannot be attributed entirely to some unexplained “fade out.” Other studies find that extensive compensatory efforts by the public schools for those farthest behind offset some of the initial gains from preschool–which is why these studies find cost-savings during the early school years.
Defenders of Head Start cite a number of other studies that find substantial effects for Head Start, including some that find that initial effects on achievement disappear. Long-term gains are attributed to unmeasured improvements in “grit,” socio-emotional development, parenting, or some other unknown cause. Yet, these other studies are not as methodologically strong as the national randomized trial and their results are sometimes implausibly large and mysterious compared to those in the rest of the research literature much of which is less favorable. The most rigorous studies of other preschool programs that find long-term gains do not see effects disappear and re-emerge. And, the national randomized trial of Head Start indicates that effects on social-emotional development and parenting are too small to produce the hoped for large long-term gains.
Weighing all of the evidence and not just that cited by partisans on one side or the other, the most accurate conclusion is that Head Start produces modest benefits including some long-term gains for children. The much maligned public schools produce larger gains in achievement beginning in kindergarten which may well erase some of Head Start’s gains, but such efforts can be costly. Head Start’s cost-savings and other benefits may well exceed its costs. Yet, that is not enough. Head Start could produce larger gains if the program was better focused and made other improvements. Reforms being implemented by the Obama administration are an important step in that direction. More are needed including substantial deregulation at the federal level that would permit greater flexibility an innovation. Unshackled from unrealistic mission expansion and agency micromanagement, and refocused on education as job one, Head Start could actually produce the results that both its critics and defenders seek.
Note: This essay was first published in the Washington Post’s “Answer Sheet.”