TY - JOUR AU - Dubé,Jean-Pierre H. AU - Fox,Jeremy T. AU - Su,Che-Lin TI - Improving the Numerical Performance of BLP Static and Dynamic Discrete Choice Random Coefficients Demand Estimation JF - National Bureau of Economic Research Working Paper Series VL - No. 14991 PY - 2009 Y2 - May 2009 UR - http://www.nber.org/papers/w14991 L1 - http://www.nber.org/papers/w14991.pdf N1 - Author contact info: Jean-Pierre H. Dube University of Chicago Booth School of Business 5807 South Woodlawn Avenue Chicago, IL 60637 Tel: 773/834-5377 Fax: 773/702-0458 E-Mail: jdube@chicagobooth.edu Jeremy T. Fox Economics Department University of Michigan 238 Lorch Hall 611 Tappan Ave Ann Arbor, MI 48104 Tel: 734-330-2854 Fax: 734-274-2331 E-Mail: jeremyfox@gmail.com Che-Lin Su University of Chicago E-Mail: che-lin.su@ChicagoBooth.edu AB - The widely-used estimator of Berry, Levinsohn and Pakes (1995) produces estimates of consumer preferences from a discrete-choice demand model with random coefficients, market-level demand shocks and endogenous prices. We derive numerical theory results characterizing the properties of the nested fixed point algorithm used to evaluate the objective function of BLP's estimator. We discuss problems with typical implementations, including cases that can lead to incorrect parameter estimates. As a solution, we recast estimation as a mathematical program with equilibrium constraints, which can be faster and which avoids the numerical issues associated with nested inner loops. The advantages are even more pronounced for forward-looking demand models where Bellman's equation must also be solved repeatedly. Several Monte Carlo and real-data experiments support our numerical concerns about the nested fixed point approach and the advantages of constrained optimization. ER -