Product Differentiation and Oligopoly: A Network Approach

76 Pages Posted: 2 Feb 2023

See all articles by Bruno Pellegrino

Bruno Pellegrino

University of Maryland - Robert H. Smith School of Business

Multiple version iconThere are 2 versions of this paper

Date Written: 2023


This paper develops a theory of oligopoly and markups in general equilibrium. Firms compete in a network of product market rivalries that emerges endogenously out of the characteristics of the products and services they supply. My model embeds a novel, highly tractable and scalable demand system (GHL) that can be estimated for the universe of public corporations in the USA, using publicly-available data. Using the model, I compute firm-level markups and decompose them into: 1) a new measure of firm productivity that accounts for product quality; 2) a metric of network centrality, which captures the extent of competition from substitute products. I estimate that, in 2019, public corporations produced consumer surplus in excess of 10 US$ trillions (against $3 trillions of profits). Oligopoly lowers total surplus by 11.5% and depresses consumer surplus by 31%. My analysis also suggests that both numbers were significantly lower in the mid-90s (7.9% and 21.5%, respectively). These results should be interpreted with care due to data limitations.

Keywords: competition, concentration, general equilibrium, market power, markups, mergers, monopoly, networks, oligopoly, text analysis

JEL Classification: D200, D400, D600, E200, L100, O400

Suggested Citation

Pellegrino, Bruno, Product Differentiation and Oligopoly: A Network Approach (2023). CESifo Working Paper No. 10244, Available at SSRN: or

Bruno Pellegrino (Contact Author)

University of Maryland - Robert H. Smith School of Business ( email )


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