Limited information is available concerning price determination in the thoroughbred yearling market. A recursive model incorporating price expectations and biological constraints is used to estimate supply and demand functions for thoroughbred horses. Empirical results characterize a market with inelastic supply and elastic demand that converges to equilibrium under static conditions. Purses were identified as the most influential variable impacting price. Comparative statics illustrate the effectiveness of purses as a policy instrument for the thoroughbred industry. Federal tax policy also was found to have a significant impact on the decisions to breed or invest in thoroughbred yearlings.