IMF-基于搜索的并购理论（英）

A Search-Based Theory of Mergers and Acquisitions Flavien Moreau; Semih Üslü WP/25/239IMF Working Papers describe research in progress by the author(s) and are published to elicit comments and to encourage debate. The views expressed in IMF Working Papers are those of the author(s) and do not necessarily represent the views of the IMF, its Executive Board, or IMF management. 2025 NOV* “The author(s) would like to thank” footnote, as applicable.© 2025 International Monetary Fund WP/25/239IMF Working Paper Research Department A Search-Based Theory of Mergers and Acquisitions Prepared by Flavien Moreau and Semih Üslü Authorized for distribution by Petia Topalova November 2025 IMF Working Papers describe research in progress by the author(s) and are published to elicit comments and to encourage debate. The views expressed in IMF Working Papers are those of the author(s) and do not necessarily represent the views of the IMF, its Executive Board, or IMF management. ABSTRACT: We develop a search-based theory of mergers and acquisitions with heterogeneous firms and endogenous search complementarities. We use this model to understand how merger incentives and the firm size distribution interact. In equilibrium, search costs and entry rates determine search intensities and shape the distribution of market power. We derive the law of motion of the firm size distribution, provide closed-form solutions, and solve for endogenous search efforts. Finally, we derive the aggregate welfare function and show how our framework can be used to simulate the impact of various antitrust policies. In particular, antitrust policy can have large effects on welfare due to the existence of multiple equilibria. RECOMMENDED CITATION: Moreau, Flavien and Semih Üslü. 2025. “A Search-Based Theory of Mergers and Acquisitions.” IMFWorking Paper 2025/239 JEL Classification Numbers: D82, D83, E40, E50 Keywords: Search; Bargaining; Mergers & acquisitions; Market power Author’s E-Mail Address: semihuslu@jhu.edu; fmoreau@imf.org WORKING PAPERS A Search-Based Theory of Mergers and Acquisitions Prepared by Flavien Moreau and Semih ÜslüA Search-Based Theory of Mergers andAcquisitions *Flavien Moreau† r⃝ Semih ¨Usl¨u‡October 14, 2025AbstractWe develop a search-based theory of mergers and acquisitions with heterogeneousfirms and endogenous search complementarities. We use this model to under-stand how merger incentives and the firm size distribution interact. In equilibrium,search costs and entry rates determine search intensities and shape the distributionof market power. We derive the law of motion of the firm size distribution, provideclosed-form solutions, and solve for endogenous search efforts. Finally, we derivethe aggregate welfare function and show how our framework can be used to simu-late the impact of various antitrust policies. In particular, antitrust policy can havelarge effects on welfare due to the existence of multiple equilibria.JEL classification: D82, D83, E40, E50Keywo