Some observers claim that compulsory school-attendance laws have little effect on students who are potential dropouts. But a new study by Joshua D. Angrist of Harvard University and Alan B. Krueger of Princeton University disputes this view. Noting that most states require students to stay in school until they reach their 16th birthday, the two economists examined attendance records of students born early and late in the calendar year. Because of school-entrance policies, children born early in the year typically enter first grade at an older age than those born late in the year. Thus, they reach 16 with less schooling and are legally free to drop out.
The study shows that a significant number do just that. Looking at people born between 1920 and 1959, Angrist and Krueger found that men that were born in the first quarter were some 10% more likely to have dropped out before graduating high school than those born in the final quarter. Moreover, those born early in the year tended to have lower earnings than those born later in the year.
Angrist and Krueger estimate that compulsory-attendance laws helped keep some 10% of potential dropouts in school in the early 1980s. They also calculate that students who were compelled to stay in school an extra year can expect to earn at least 7% more in their lifetimes than if they had dropped out.