Monopoly Pricing with a Public Option

2025-07-17

AI Summary

This paper examines the competitive interaction between a profit-maximizing monopolist and a free but capacity-constrained public option, analyzing its welfare implications. Using game-theoretic and microeconomic modeling, we characterize equilibrium supply and pricing strategies in mixed public-private markets. We find that the monopolist strategically restricts its supply to raise consumers’ willingness-to-pay, thereby exacerbating congestion in the public option. Counterintuitively, expanding public capacity may reduce both producer surplus and consumer welfare—by weakening the disciplining effect of the public option, it can induce inefficient queuing or quality deterioration. Moreover, under certain conditions, introducing the monopolist—even absent quality differentiation—can increase aggregate consumer surplus. These results challenge the conventional intuition that public capacity expansion unambiguously improves welfare, offering a rigorous, counterintuitive theoretical foundation for policy design in mixed markets such as housing, education, and healthcare.

Technology Category

• Game Theory and Economic Paradigms: Mechanism Design
• Multiagent Systems: Mechanism Design
• Search and Optimization: Mixed Discrete/Continuous Search

Application Category

• Economics, Online Markets and Human Computation: Uses of LLMs and GenAI for marketplace design, bidding, and strategic interactions
• User Modeling, Personalization and Recommendation: Practical large-scale studies of user experience
• Security and Privacy: Large-scale security measurements

Abstract

This paper examines how a profit-maximizing monopolist competes against a free but capacity-constrained public option. The monopolist strategically restricts its supply beyond standard monopoly levels, thereby intensifying congestion at the public option and increasing consumers' willingness-to-pay for guaranteed access. Expanding the capacity of the public option always reduces producer welfare and, counterintuitively, may also reduce consumer welfare. In contrast, introducing a monopolist to a market served only by a capacity-constrained public option unambiguously improves consumer welfare. These findings have implications for mixed public-private markets, such as housing, education, and healthcare.

Problem

• Monopolist competes with free public option
• Public option capacity affects welfare outcomes
• Implications for mixed public-private markets

Innovation

• Monopolist restricts supply strategically
• Public option capacity affects welfare
• Mixed markets benefit from monopolist entry