With all the recent discussion about teaching ethics in business schools, some of us may have started to forget another factor involved in choosing to attend business school: moving up the pay scale.

It’s good to remember that, according to the U.S. Census Bureau , there is about a 20% increase in salary between a Bachelor’s degree and a Master’s degree, and that’s taking into account all of the Master’s degrees out there!

Yet it seems that to make a lot of money you may have to spend a lot of money. A new study commissioned by Bloomberg BusinessWeek has found that there is in fact a correlation between an MBA’s average salary and where he or she went to business school.

Harvard, where students spend an average of $106,000 for their two years of education, comes in first. According to the study, the median income for HBS grads over a 20 year period is $3,867,903. Wharton is second and has the highest average salary at graduation: $137,000.

But if you’re looking for a large percentage increase in salary over time, check out George Washington University, where the average salary increase in 20 years is 114 percent.

It looks like  getting an MBA from a top school has its benefits. Added incentive to get a great GMAT score!