Colorado College uses an economic system to allocate scarce course seats: annually during a sealed-bid auction, each student receives nontransferrable, nonbankable currency with which to bid on courses. We estimate an instrumental variables probit model to determine whether particular student populations are a) implicitly wealthier, having the ability to afford more expensive electives, or b) more risk-averse, choosing to avoid ambiguity by bidding more strongly and/or remaining in a class rather than selecting another after pre-registration. Beyond the anticipated department-specific and instructor-specific effects attributable to popular majors or charismatic instructors, we find strong evidence that students bid more strongly for courses that have perceived scarcity of seats, courses that offer a higher expected grade, courses taught by an instructor similar to themselves, or courses with special attributes like limited enrollment or field trip components. We also find evidence of some populations being more willing to “shop around” for new class experiences after the pre-registration period.