* Discount rate of 6% (we're talking about an asset with a 40-year lifespan and zero terminal value).
* $25K in annual school costs.
* $25K in annual opportunity costs. (May be conservative for people who are college material but didn't get a degree.)
* Four years to complete the degree. Which is very aggressive.
* $23K earnings differential. (The current average.)
* Forty years of post-degree work.
In this model, you get to breakeven 26 years after you start school. So, to the current high-school senior: assuming the job market in 2036 looks pretty much like it does now, treat these projections as solid.
It gets worse. If you assume a more realistic graduation timeframe of six years, the value is -$18K after 40 years. Of course, you can keep working; you'll hit breakeven after 54 years (at age 72).
See sheet two for my assumptions:
https://spreadsheets.google.com/ccc?key=0AjzB7A88UMCBdGVrUUN...