Note: This is post #56 in a weekly video series on basic microeconomics.

Why do wages in America differ greatly among workers? One reason, says economist Alex Tabarrok, includes differences in human capital—tools of the mind. Education is one of the biggest investments people make to increase their human capital. Which college majors offer the greatest returns? And are all returns on education due to human capital? In this video by Marginal Revolution University, Tabarrok explains how a college degree can “signal” other factors, and discusses what monly known as the “sheepskin effect.”

(If you find the pace of the videos too slow, I’d mend watching them at 1.5 to 2 times the speed. You can adjust the speed at which the video plays by clicking on “Settings” (the gear symbol) and changing “Speed” from normal to 1.25, 1.5 or 2.)

Previous in series: Is education signaling or skill building?