Robin Hanson has been arguing that perhaps along with redistributing income, we should redistribute grades. I have myself been known to argue that perhaps we should consider redistributing PhDs and Harvard professorships, to limited success with the sort of people who have those things. So I'm probably prone to be rather partial to the conundrums raised by this sort of proposal--and particularly this: "My point isn't to say one can't come up with reasons to treat these differently. One could, for example, argue that we prefer differing school signals to help employers sort people into jobs, to achieve higher productivity so that the pie is bigger when we redistribute money. My point is that most people can't think of such reasons, making it pretty unlikely that such reasons are the cause of their opinions..."
XPostFactoid gives himself an hour to come up with some arguments against this proposal, and comes up with this:
Comparing apples to oranges: "GPA is more tightly tied to individual performance than earnings are. Granting that a) grading is an imperfect measure of the quality of student input, and b) earnings bear some relationship to performance, it's still true that student performance bears a closer relationship to grade than the social utility of the average person's work does to that person's earnings" So the correct metric by which we assess grades is accuracy (does it correlate with performance) while the correct measure of income is whether it serves some larger social purpose. Obviously, comparisons should be of like to like: either how accurately income/GPA are tied to performance, or how accurately they are tied to social utility. It's not clear that GPA would win on either score.
Begging the question: Of course, the latter comparison simply assumes what it wants to prove: that there is "social utility"; that this quantifiable concept differs in some way that we can know conclusively differs from income distribution; and that it differs in a way that can most reasonably be corrected by redistributing income (rather than, say, changing bad rules which result in the accumulation of great incomes from activities that generate no or little social utility.) These are big questions, and no attempt is made to prove them, or even to simply say "I believe that . . . " rather, they are simply asserted as fact. The author goes on to make similarly sweeping claims about the purpose and right of taxation.
Overgeneralizing "As Hanson intimates, developing one's value in the workplace is largely dependent on learning things in school. You cannot progress adequately through our educational system without having your performance measured." Even assuming this is true--and the second statement is at least open to question--it is not true of all education; it's true of a fairly limited set of skills in language, math, and science. Virtually everyone needs basic reading and math in order to earn income. Virtually no one needs American history or art.
Post-hoc rationalization of the status quo Moreover, this is not a good description of how the educational system actually works, making this sound like exactly the sort of post-hoc reasoning that Hanson describes in his post. We put the least focus on GPAs at the age when students are learning the most important skills: basic math and reading. We put the most emphasis on them in junior and senior year, when it is already too late for students who have not learned basic skills. If the purpose of GPAs were to help students learn skills that would be useful in the workplace, we should see the opposite effect.
Non sequitur "Income redistribution in the U.S. is very moderate. No one who makes a lot of money has cause to complain that the state is depriving him or her of the fruits of labor. And by multiple measures of national well-being, humans thrive best in societies that invest in commonwealth, that is, do their utmost to provide the conditions for a decent life to all and to moderate without eliminating disparities of wealth." Of course, this doesn't tell us whether we should redistribute income, (or grades), only whether we are.
Hand waving "While objectively it's all but impossible to identify any of our accomplishments as products of free will and therefore merit -- IQ is as much a matter of luck as the material wealth of the family we're born into-- we have to live as if individual effort matters and reward the fruits of that effort; we have to motivate achievement. That's true both in school and workplace: good work in school should lead to opportunities to learn more, and ultimately to do responsible work, and good performance at work should lead to more responsibility and the chance to perform more complex tasks. This necessitates tying GPA to individual performance -- and, to a degree, as the failure of communism has taught us, pay to individual performance. But the latter relationship is not absolute, because each of us also has an interest in being part of a commonwealth, per point 3 above, and because each of gets more than merely financial rewards from work." The author has still failed to distinguish GPA from income in any meaningful way; rather, he simply announces that they're different.
As Robin Hanson says, I think you can distinguish the two. For example, to the extent that the function of education is signaling, messing up the signal would help no one; it would simply destroy the value of the signal. Perhaps the sorting and competitive impetus provided by GPAs are more valuable to individuals and society than those functions are when they're being served by income.
But the poor quality of the arguments for difference does not bode well. They suggest that most of us just want to redistribute income because, well, we wanna . . . not because we have any particularly good reason. Which was Robin's point in the first place.