Equilibrium Models with Dynamic Demand and Dynamic Supply

Abstract

This dissertation comprises two studies of equilibrium models with both dynamic demand and dynamic supply sides. The first is an empirical study of the US video games industry, and the second is a theoretical study.

Chapters 1 and 2 develop a model for quantifying the role of social learning in consumers’ dynamic demand and finding optimal intertemporal prices for profit maximizing firms in a market populated by forward-looking social learners. Optimal prices are a result of a Markov perfect equilibrium played between the firm and the consumers. Nested in the market equilibrium is a demand equilibrium played among consumers who make the “right” purchase/wait decisions given endogenously produced product information. The empirical exercises are conducted in two steps. The first step estimates demand parameters, including those associated with social learning. Endogeneity of prices is remedied with a pseudo pricing policy function of relevant state variables. In the second step, optimal prices are found by the Mathematical Programming with Equilibrium Constraints (MPEC) approach. The model is applied to the US video games industry with sales data of PlayStation 3 games. The results reveal that (1) compared to static social learning, forward- looking social learning reduces equilibrium profits of games in the sample by $5.2M (28.4%) on average; (2) an incorrect belief of consumers’ forward-looking behavior reduces a firm’s profits by a maximum of 29.92%. These results indicate great value for researches on consumers’ forward-looking social learning behavior.

In chapter 3 we study the effect of adding strategic buyers to the computational model of dynamic price competition when sellers experience learning-by-doing and organizational forgetting developed by Besanko et al. (2010) (BDKS). The addition is motivated by the presence of repeat buyers in many industries where learning- by-doing has been documented, and the role that the assumption of a monopsony strategic buyer has played in the theoretical literature. We characterize the degree of strategic buyer behavior using a single parameter, and show that even quite limited strategic behavior changes the equilibrium correspondance by almost entirely eliminating the multiplicity of equilibria emphasized by BDKS, and ensuring that no seller is likely to dominate the industry in the long-run. We examine how the welfare of both buyers and sellers varies with the degree of strategic buyer behavior.