<p>Numbers for classes are consistent across the 5Cs. I looked at the catalog and found Principles of Microeconomics is Econ 52, and is being offered at Pomona, Scripps, and Pitzer next semester. Econ 50 is Principles of Economic Analysis, and seems unique to CMC. At HMC I think only Prag teaches Micro, probably every other spring. I think the 54 was a typo.</p>