Three of the five are economics courses! The full report by Sophia M. Armenakas (The Crimson) is available here. Without further ado, here are the top five: (1) Economics 10b: “Principles of Economics” (455 students); (2) Life Sciences 1b: “An Integrated Introduction to the Life Sciences” (443 students); (3) Economics 1152: “Big Data” (enrollment number not specified in the Crimson article); (4) Psychology 18: “Abnormal Psychology” (415 students); and (5) Statistics 104: “Introduction to Quantitative Methods for Economics” (336 students). Postscript: I wonder what the five least popular courses are? Hat tip: Tyler Cowen.