Greg Mankiw links to a chart which provides the evidence (or click here for the larger version). The answer is physics (1899), math (1877), computer science (1862) and, of course, economics (1857) … followed by a handful of engineering majors and philosophy. Though, as Brian Leiter has happily reported in the past, and is still true using more recent data, philosophy majors come in slightly ahead of economics majors (157.4 to 156.6) on the LSAT (they are #2 and #3, respectively, behind mathematics) — though it should be noted that economics sustains this average with nearly twice as many students. And if academia is not for you, there remains the mounting evidence that the market for legal services values economic education, as do markets generally.