I just ran across some more striking evidence that ambition really matters.  James Rosenbaum’s “College-For-All: Do Students Understand What College Demands?” (Social Psychology of Education, 1998) shows degree completion as a function of high school students’ GPA and educational aspirations.

Exhibit A: Percentage of high school seniors who plan to get a BA who successfully do so.


Exhibit B: Percentage of high school seniors who plan to get an AA who successfully do so.


The simplest reading of the evidence is that getting a BA is easier than getting an AA!  After all, holding high school GPA constant, students are vastly more likely to complete the BA.  Over two-thirds of A-students who plan to get a BA succeed; less than half of A-students who plan to get an AA succeed.  This pattern extends all the way down to the weakest students.

A better interpretation, though, is that seniors who say they want a BA have a lot more ambition than their peers.  As a result, they are – holding grades fixed – markedly more likely to achieve their goal despite its intrinsic difficulty.  Seniors who say they only want an AA, in contrast, simultaneously aim low and fall short.

This probably doesn’t mean that students can improve their prospects merely by mouthing the words, “I plan to get a BA.”  The reasonable interpretation, rather, is that people who place a high value on conventional success are much more likely to achieve it.  A B student who says, “I want a BA” is as likely to cross his personal finish line as an A student who says, “I want an AA.”  And as far as I know, no estimate of the return to education properly adjusts for this factor.