The St Louis Federal Reserve Bank did a study on schooling and subsequent income: Measuring the Effect of School Choice on Economic Outcomes. Money (!) quote:
The graph shows that students who attended private and Catholic schools earned 13.1 percent and 13.9 percent more, respectively, than those who attended public schools. Students who attended urban schools earned 5.3 percent less than those who attended suburban schools, while those who attended rural schools earned 10.8 percent less than those who attended suburban schools. When looking at school-level factors, we found that students from schools with the lowest dropout rates and the lowest percentage of students in remedial courses earned 11.8 and 0.7 percent more, respectively, than those attending schools with average rates; students at schools with the lowest teacher base salaries earned 2.2 percent less than those at schools with average teacher salaries. Overall, one can extrapolate from the figure that individuals who attended suburban Catholic high schools with few dropouts, few students in remedial courses and higher teacher base salaries had the highest earnings. These findings support both the resource- and environment-based theories of school quality.
Yes, as I’m sure we can all see, correlation absolutely proved causation in this case. It’s all about “school quality”. Or maybe getting your palm slapped with a ruler by an irascible nun causes the subsequent increase in income. Students who have experienced that probably never show up late for work.