A Dynamic Quality Ladder Model with Entry and Exit: Exploring the Equilibrium Correspondence Using the Homotopy Method

Working Paper: CEPR ID: DP7560

Authors: Ron N. Borkovsky; Ulrich Doraszelski; Yaroslav Kryukov

Abstract: This paper explores the equilibrium correspondence of a dynamic quality ladder model with entry and exit using the homotopy method. The homotopy method facilitates exploring the equilibrium correspondence in a systematic fashion; it is ideally suited for investigating the economic phenomena that arise as one moves through the parameter space and is especially useful in games that have multiple equilibria. We discuss the theory of the homotopy method and its application to dynamic stochastic games. We then present the following results: First, we find that the more costly and/or less beneficial it is to achieve or maintain a given quality level, the more a leader invests in striving to induce the follower to give up; the more quickly the follower does so; and the more asymmetric is the industry structure that arises. Second, we show that the possibility of entry and exit alone gives rise to predatory and limit investment. Third, we illustrate and discuss the multiple equilibria that arise in the quality ladder model, highlighting the presence of entry and exit as a source of multiplicity.

Keywords: Computation; Dynamic Stochastic Games; Homotopy Method; Markov Perfect Equilibrium

JEL Codes: C63; C73


Causal Claims Network Graph

Edges that are evidenced by causal inference methods are in orange, and the rest are in light blue.


Causal Claims

CauseEffect
Cost-benefit dynamics of quality maintenance (L15)Leader's investment behavior (G11)
Leader's investment behavior (G11)Follower's exit decision (D79)
Follower's exit decision (D79)Asymmetric industry structure (L13)
Possibility of entry and exit (C62)Predatory and limit investment (G11)
Entry and exit (Y60)Multiplicity in the Ericson-Pakes framework (C59)

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