Principal investigator: Bruno Benevit.
Original title: The Effect of Age at School Entry on Educational Attainment: An Application of Instrumental Variables with Moments from Two Samples.
Authors: Joshua D. Angrist and Alan B. Krueger.
Location of the Intervention: U.S.
Sample Size: 112.000 children.
Sector: Economics of Education.
Primary Variable of Interest: Schooling.
Type of Intervention: School entry age.
Methodology: IV
Summary
Education plays a fundamental role in various social determinants of people's lives. Given its importance, the age of entry into the education system can be a relevant factor in explaining the educational attainment achieved in adulthood. Compulsory school attendance policies can affect this determinant. In this sense, this study considered data from the 1960 and 1980 United States Census to analyze how the country's compulsory school attendance law impacted the educational attainment of the affected cohorts. Through instrumental variable models formulated by the authors, the results suggest that compulsory attendance laws induce approximately 10% of students to remain in school.
- Policy Problem
Formal education is fundamental not only for individuals but for society as a whole. Given its importance, the age of school entry is a significant factor that can influence students' educational performance, having long-term repercussions for them. Thus, policies of compulsory school attendance have great potential to influence this behavior.
In the context of the United States, the authors of this study presented a model that assumes children enter school in the fall of the year they turn six and are legally required to remain in school until they turn sixteen (ANGRIST; KRUEGER, 1992). In this situation, a child's birth date can directly affect the amount of time they will spend in school before reaching the minimum age to leave their studies. Students born at the beginning of the year, who turn sixteen earlier, tend to spend less time in school compared to those born at the end of the year, resulting in different levels of education attained. This phenomenon creates a natural experiment that allowed researchers to investigate how the age of school entry impacts individuals' educational trajectories.
- Policy Implementation Context
Studies have shown that many students drop out of school as soon as they reach the minimum legal age, suggesting that compulsory school attendance laws play a key role in keeping these students in school longer.
According to Angrist and Krueger (1991), data from the 1960s, 1970s, and 1980s censuses revealed that school dropout rates increase significantly around the age of sixteen in states where that is the minimum age allowed to leave school. In contrast, states with stricter requirements, extending the minimum age to seventeen or eighteen, show lower dropout rates. This evidence indicates that the age of school entry and compulsory attendance policies are interconnected, influencing not only when students begin their studies but also how long they remain in school, thus affecting their overall educational attainment and future potential.
- Evaluation Details
To estimate the relationship between school entry age and education attainment, data from two United States censuses were used. The sample containing school entry age was drawn from the 1960 Census, while the sample containing years of education was drawn from the 1980 Census. Both datasets were restricted to males born between 1946 and 1952. The study focused on the cohort of males born between 1946 and 1952 because they were in elementary school during the 1960 Census.
To determine the school entry age, entry age standards were compared in two groups of states with different cut-off dates for first-grade admission. States that admitted children who turned 6 by September 30 or October 1 were compared with states that allowed entry for children who turned 6 by December 31 or January 1. These variations helped analyze the influence of state laws on school entry age.
The youngest child in the 1960 sample was 7 years old, above the legal minimum age for school attendance in most states. First-grade entry age was calculated based on the student's age and grade level, assuming no child was held back or advanced after entering school. The approach used takes into account age, measured in trimesters on Census Day (April 1, 1960), and the grade level the student was enrolled in. Completed years of schooling were obtained from the 1980 Census, although this census reports only complete years, not trimesters.
- Method
The study employed the instrumental variables (IV) method to estimate the relationship between school entry age and years of schooling completed. The sample considered included males born between 1946 and 1952, with first-grade entry age estimated from 1960 Census information and years of schooling obtained from the 1980 Census. Thus, this method was based on the assumption that children were not held back or advanced a grade after entering school, allowing the calculation of entry age from the age and grade level reported in the census.
The use of instrumental variables, in this case, allows us to estimate the relationship between school entry age and years of schooling completed, controlling for possible correlations between entry age and other unobserved factors that may influence educational outcomes. This approach offers a robust way to investigate the impact of entry age on schooling, even in the absence of perfect data on the exact age of school entry.
To validate these estimates, entry age patterns were compared in states with different cutoff dates for first-grade admission. States with cutoff dates in the third quarter were compared with states with cutoff dates in the fourth quarter, analyzing how these cutoff policies affect children's entry age. Comparing entry age patterns between these two groups of states provides further verification of the accuracy of heterogeneous entry age estimates, allowing for the estimation of effects associated with different entry ages.
- Main results
The results of the study on school entry age indicated a negative relationship between school entry age and years of schooling completed. Specifically, the estimates revealed that, in general, children who enter school at an older age tend to complete fewer years of education. The analyses were performed using different specifications of cohort trends in education, and most specifications resulted in significant coefficients, reinforcing this relationship.
The analysis also showed that this relationship remains robust even when controlled for different model variations and adjustments for cohort trends. Furthermore, the estimates obtained remained significant when considering interactions between year and quarter of birth with place of birth, and model fit tests suggest that the assumption of seasonality in birth as a valid instrument for school entry age is plausible. These results support the model proposed by the authors that relates school entry age to years of education completed, suggesting that minimum school entry age policies can have significant impacts on students' educational trajectories.
- Lessons in Public Policy
In this article, the authors investigated the impact of school entry age on years of schooling completed. The results presented indicated that individuals who enter school at older ages tend to achieve a lower level of schooling. This effect persists even after controlling for cohort trends and other demographic variables. Additionally, the authors found evidence that approximately 10% of men born between 1946 and 1952 were impacted by compulsory schooling laws, remaining in school for an additional period as a result of these public policies.
The evidence presented in this article helps to understand the factors that influence educational performance, providing support for public policy makers. The authors highlight that, given the impact of school entry age, revising minimum entry age policies can optimize educational outcomes. Furthermore, adapting these policies can help implement measures that better align educational requirements with child development, contributing to the overall improvement of the education system.
References
ANGRIST, JD; KRUEGER, AB Does Compulsory School Attendance Affect Schooling and Earnings? The Quarterly Journal of Economics, v. 106, no. 4, p. 979–1014, 1991.
ANGRIST, JD; KRUEGER, AB The Effect of Age at School Entry on Educational Attainment: An Application of Instrumental Variables with Moments from Two Samples. Journal of the American Statistical Association, v. 87, no. 418, p. 328–336, jun. 1992.
