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Journal article
Quantifying the gap between equilibrium and optimum under monopolistic competition
Kristian Behrens, Giordano Mion, Yasusada Murata and Jens Suedekum November 2020
Paper No' :

Tags: oligopoly and other forms of market imperfectiond50 - generall13 - oligopoly and other imperfect markets

Equilibria and optima generally differ in imperfectly competitive markets. Although this is well understood theoretically, it is unclear how large the welfare distortions are in the aggregate economy. Do they matter quantitatively? To answer this question, we develop a multisector monopolistic competition model with endogenous firm entry and selection, productivity, and markups. Using French and UK data, we quantify the gap between the equilibrium and optimal allocations. We find that inefficiencies in the labor allocation and entry between sectors, as well as inefficient selection and output per firm within sectors, generate welfare losses of about 6%–10% of GDP. © The Author(s) 2020.