A bunch of people e-mailed me about the Drop Out and Grow Rich article I posted yesterday. A friend of mine pointed out a few things, most importantly that I failed to give the college grad interest on his money. Fixing that (and making him pay interest if he was negative, but only after the first 4 years of college) put him very close to the high school grad with private school money. Never charging him interest for being negative got him slightly above that same person.
Then it was pointed out that the difference in earnings wasn't 900k as the college-mongers claimed. It was more like 1.3mil. I had no good data on salary increases, so I assumed the inflation rate. I guess it stands to reason that after a while job experience means more than the degree, so the gap gets smaller.
If I fudged the grad's income to equal a 900k lifetime earnings difference, the Dropout with Private School money is again the winner, but is still followed closely by the grad. If I fudge the dropout's starting income (to $29,692) to get the 900k difference, the grad still beats the dropout with public level money, but only by 300k. Also, the dropout would be beating him until age 58.