Research shows that children who are older when they begin school come to the classroom with stronger cognitive, language, social, and motor skills. This is not surprising; these children are more mature and have been exposed to more parenting time than their younger peers, so they score higher on cognitive exams and tests of other skills.

New research from HCEO Inequality Measurement, Interpretation, and Policy Network member Sebastian Gallegos and colleague Pablo Celhay suggests that evidence of these stronger skills changes parent’s expectations for their child’s achievement. Parents of children with early skill advantages were more likely to believe their children would complete higher education, such as college, graduate school, and technical careers. With high expectations for their children’s future, parents invested more in books, laptops, and internet access for their child.

This paid off in the long run. Tracking these children over 20 years, they found this increased parental investment was associated higher test scores in school, higher rates of college attendance. and enrollment in selective colleges.

The study, recently published in the Journal of Human Resources, takes advantage of an age-based admissions rule in Chile. children who have not turned 6 by June 30 must wait until the following school year to enroll. Thus, children born in July can be almost a full year older than their peers when they start school.

“The age that you start school matters. There is a long literature telling us if you delay the entrance of school, children do better,” says Gallegos, an assistant professor at the Escuela de Negocios at Universidad Adolfo Ibánez. While in one sense it’s obvious that older children would have developed stronger skills, this also seemingly contradicts abundant evidence on the importance of early education to begin building human capital and a foundation for learning in the first years of life. Gallegos says this study attempts to better understand early skill gaps and the drivers of long-term outcomes.

The study tracked standardized exam scores and educational attainment for about 1 million first graders and 1 million eight-grade students in Chile. Their results confirmed that older children start first grade with a skill advantage that translates into higher grades and passing rates in first grade. The July-born students also had higher standardized test scores in fourth grade.

The study’s novel contribution lies in capturing parents’ causal response to their child’s academic performance. Researchers administered surveys to parents and students in the fourth grade, asking questions to capture parents’ financial and time investments. Students were asked if their parents helped them study, were aware of their grades, and demanded good grades.

Responses showed that parents of July-born children interpret the early skill advantage as a signal of ability and potential, and they make greater financial investments in their children. July-born children are 10 percent more likely to have a computer at home, 20 percent more likely to have an Internet connection, and 8 percent more likely to have 10 or more books at home. Parents are 5 percent more likely to spend above the median of monthly expenditures for school items.

However, parents did not make greater time investments in time spent boosting their child’s academic skills.  “I tend to think, if we had better measures of time investments, we would probably be able to find some effects,” Gallegos notes.

Another key contribution of the study was tracing the long-run impact of the early skill gaps. Researchers found that July-born students were 6 percent more likely to take the national college entrance exam, and they scored higher. College enrollment was 15 percent higher for July-born students, 20 percent higher in selective universities, and 14 percent higher in STEM programs.

All of the effects on financial investments and college enrollment were more pronounced for low-income children. Given the well-documented disadvantages and skill gaps that start early for children born into poverty, it may seem prudent to enroll those children in enriching educational environments as soon as possible. Gallegos says this finding indicates that when children start school later and do better, the positive feedback will encourage parents to invest more and help close the skill gaps. “You’re telling a group of parents and children consistently that these kids have a shot. And anything that affects the probability of college attendance is going to be huge,” he says.

Gallegos acknowledges that these measurable early skill differences are based purely on chance—the timing of birth. “If we were controlling for age when giving parents feedback on their child’s performance, that skill advantage would disappear.” However, the power of the signal parents receive is real, and motivates them to invest more in their child.

“We know parental investments are important. The bottom line of our work is that we can really modify the future of kids if we send signals to parents. We now know better about how to affect those parental investments,” he says.

Another implication for the study is that parents could benefit from more nuanced feedback on their child’s performance. Some high-ability children might be performing less well than peers simply because they are younger. If teachers could provide more context around performance or provide age-adjusted data, more parents might be motivated to boost their investment in their child’s learning.

“Most kids will show some skills in a particular domain. We don’t want to overwhelm parents, but if we can provide them with positive signals about their kids based on data, we might help them modify their investment parents behavior,” he says. “Now that we’ve disrupted the field with this finding of causal effects on parental investments and expectations, the next question is how do other relevant actors such as teachers react. This evidence would contribute to complete the picture, identifying the nuts and bolts of the educational production function ”

Toni Shears