Can earlier college and later dropouts fit together?

Earlier, I estimated that raising the dropout age to 18 would mean adding almost 10,000 students to our public schools, at a cost of around $75 million--plus the costs of adding classroom space to accommodate them.

Today, writing about proposals to let student test out of high school earlier, I saw a potential solution.  If 8,000 students finished high school a year early and 2,000 more finished two years early, that would free both the space and the money to serve the added students we want to keep in school.

I should, of course, add some cautions.

On the dropout side,  my estimate of 10,000 prevented dropouts is only an estimate, and it's  based only on students who are tracked as dropping out.  That is, I assumed that several thousand students who somehow evaporate between grade 8 and grade 12 will not be found and added to the count.

On the early-exit side, my numbers are just guesswork about how many students might qualify to finish early and how many of those would want to do so: I haven't seen any evidence to support those guesses.

Finally, and most important, a responsible early-exit plan requires a robust assessment, one that gives a sturdy indication that students really are college-and-career-ready.  Work has begun to create that kind of test, but it's far from ready for broad application in  major life-decisions by Kentucky teenagers.