Another permutation of the U.S. News Ranking.
My school comes out at #4 on this one, so I'm inclined to be impressed. The idea of "efficiency" is "Spending per student for each point in the overall U.S. News score." That is, the thing schools are visualized as competing for is U.S. News rank, and the less money you spend to get to whatever rank you've been assigned on the master ranking — "Best Law Schools" — the better you do on this "efficiency" ranking.
Another way of looking at this is — to get back to a popular old activity among law professors — is to impugn the master ranking. Here, one would say that what you can infer from this new chart is that many schools are simply buying their way up the rankings, overshadowing some deeper, truer, more substantive qualities that are revealed if the things money can buy are stripped away.
That's how folks tend to talk around here.