No matter the college, a class in the principles of microeconomics is likely to cover the discipline's greatest hits. Opportunity cost? Check. Supply and demand? Ditto. The same goes for such topics as comparative advantage, elasticity, and market structures. But these touchstones of the curriculum may only modestly influence what a student actually learns. What matters more are a course's unspoken attributes that colleges rarely make plain and about which students almost never ask: For what sort of student is the course really meant? How does the professor teach and assess the material? And what does he or she think the discipline is all about? The importance of these factors became clear during a recent semester-long experiment during which this author audited principles-of-microeconomics courses at three institutions. As questions proliferate about the value of college, those outside academe are wondering what a course's name really signifies on a graduate's transcript. What would these three building-block classes say about the goals and rigor of undergraduate education, and about colleges' efforts to engage students? Each institution chose the professor whose section was audited. One was a research-intensive private institution, George Washington University; the second was a regional public, George Mason University; and the third was an online for-profit, the University of Phoenix. The professors had the same basic goal: teaching students how to think like economists. And each said that meant cultivating a scrupulous style of analysis, one in which a proposal's costs and benefits, both seen and unseen, are carefully examined. From that common origin, however, the courses diverged.