We model a market for a skill in short supply and high demand, where the presence of charlatans (professionals who sell a service they do not deliver on) is an equilibrium outcome. In the model, reducing the number of charlatans through regulation lowers consumer surplus because of the resulting reduction in competition among producers. Producers can benefit from this reduction, potentially explaining the regulation we observe. The effect on total surplus depends on the type of regulation. We derive the factors that drive the cross‐sectional variation in charlatans (regulation) across professions.

We estimate risk-free interest rates unaffected by convenience yields on safe assets. We infer them from risky asset prices without relying on any specific model of risk. We obtain interest rates and implied convenience yields with maturities up to three years at a minutely frequency. Our estimated convenience yield on Treasuries equals about 40 basis points, is larger below three months maturity, and quadruples during the financial crisis. In high-frequency event studies, conventional and unconventional monetary stimulus reduces our rates more than the corresponding Treasury yields, thus broadly affecting rates even outside the narrow confines of the fixed-income market.