IDEAS home Printed from
   My bibliography  Save this paper

Why Mergers Reduce Profits and Raise Share Prices: A Theory of Preemptive Mergers


  • Sven-Olof Fridolfsson
  • Johan Stennek


We explain the empirical puzzle why mergers reduce profits and raise share prices. If being an "insider" is better than being an "outsider," firms may merge to preempt their partner merging with a rival. The stock-value of the insiders is increased, since the risk of becoming an outsider is eliminated. We also explain why shareholders of targets gain while acquirers typically break even. These results are derived in an endogenousmerger model, predicting the conditions under which mergers occur, when they occur, and how the surplus is shared. ZUSAMMENFASSUNG - (Warum Fusionen Profite reduzieren und Aktienpreise steigen lassen) Es wird ein "Mechanismus der Gewinnung eines Vorsprungs durch Fusion" aufgezeigt, der eventuell das empirische Rätsel, warum Fusionen Profite reduzieren und Aktienpreise steigen lassen, erklären kann. Eine Fusion kann starke negative externe Effekte bei den Unternehmen auslösen, die nicht an der Fusion beteiligt sind. Wenn es besser ist ein "Insider" zu sein als ein "Outsider", kann es sein, dass Firmen Fusionieren um dem zuvorzukommen, dass ihre Partner mit jemand anderem fusionieren. Desweiteren ist der Wert eines fusionierenden Unternehmens vor der Fusion niedrig, da er das Risiko ein Outsider zu werden reflektiert. Diese Ergebnisse werden aus einem Modell endogener Fusionen abgeleitet, welches die Bedingungen unter denen eine Fusion stattfindet, wann sie stattfindet und wie der Überschuss verteilt werden wird, vorhersagt.

Suggested Citation

  • Sven-Olof Fridolfsson & Johan Stennek, 2001. "Why Mergers Reduce Profits and Raise Share Prices: A Theory of Preemptive Mergers," CIG Working Papers FS IV 01-26, Wissenschaftszentrum Berlin (WZB), Research Unit: Competition and Innovation (CIG).
  • Handle: RePEc:wzb:wzebiv:fsiv01-26

    Download full text from publisher

    File URL:
    Download Restriction: no

    Other versions of this item:

    References listed on IDEAS

    1. Bradley, Michael & Desai, Anand & Kim, E. Han, 1988. "Synergistic gains from corporate acquisitions and their division between the stockholders of target and acquiring firms," Journal of Financial Economics, Elsevier, vol. 21(1), pages 3-40, May.
    2. John C. Harsanyi & Reinhard Selten, 1988. "A General Theory of Equilibrium Selection in Games," MIT Press Books, The MIT Press, edition 1, volume 1, number 0262582384, July.
    3. Mitchell, Mark L. & Mulherin, J. Harold, 1996. "The impact of industry shocks on takeover and restructuring activity," Journal of Financial Economics, Elsevier, vol. 41(2), pages 193-229, June.
    4. Farrell, Joseph & Shapiro, Carl, 1990. "Horizontal Mergers: An Equilibrium Analysis," American Economic Review, American Economic Association, vol. 80(1), pages 107-126, March.
    5. Joseph Farrell & Garth Saloner, 1988. "Coordination through Committees and Markets," RAND Journal of Economics, The RAND Corporation, vol. 19(2), pages 235-252, Summer.
    6. Horn, Henrik & Persson, Lars, 2001. "Endogenous mergers in concentrated markets," International Journal of Industrial Organization, Elsevier, vol. 19(8), pages 1213-1244, September.
    7. Kamien, Morton I. & Zang, Israel, 1991. "Competitively cost advantageous mergers and monopolization," Games and Economic Behavior, Elsevier, vol. 3(3), pages 323-338, August.
    8. Stulz, Rene M & Walkling, Ralph A & Song, Moon H, 1990. " The Distribution of Target Ownership and the Division of Gains in Successful Takeovers," Journal of Finance, American Finance Association, vol. 45(3), pages 817-833, July.
    9. Morton I. Kamien & Israel Zang, 1987. "The Limits of Monopolization Through Acquisition," Discussion Papers 754, Northwestern University, Center for Mathematical Studies in Economics and Management Science.
    10. Ramon Fauli-Oller & Massimo Motta, 1996. "Managerial Incentives for Takeovers," Journal of Economics & Management Strategy, Wiley Blackwell, vol. 5(4), pages 497-514, December.
    11. Schwert, G. William, 1996. "Markup pricing in mergers and acquisitions," Journal of Financial Economics, Elsevier, vol. 41(2), pages 153-192, June.
    12. Eckbo, B. Espen, 1983. "Horizontal mergers, collusion, and stockholder wealth," Journal of Financial Economics, Elsevier, vol. 11(1-4), pages 241-273, April.
    13. Stephen W. Salant & Sheldon Switzer & Robert J. Reynolds, 1983. "Losses From Horizontal Merger: The Effects of an Exogenous Change in Industry Structure on Cournot-Nash Equilibrium," The Quarterly Journal of Economics, Oxford University Press, vol. 98(2), pages 185-199.
    14. Nilssen, Tore & Sorgard, Lars, 1998. "Sequential horizontal mergers," European Economic Review, Elsevier, vol. 42(9), pages 1683-1702, November.
    15. Horn, Henrik & Persson, Lars, 2001. "The equilibrium ownership of an international oligopoly," Journal of International Economics, Elsevier, vol. 53(2), pages 307-333, April.
    16. Perry, Martin K & Porter, Robert H, 1985. "Oligopoly and the Incentive for Horizontal Merger," American Economic Review, American Economic Association, vol. 75(1), pages 219-227, March.
    17. Michael J. Fishman, 1988. "A Theory of Preemptive Takeover Bidding," RAND Journal of Economics, The RAND Corporation, vol. 19(1), pages 88-101, Spring.
    18. repec:hhs:iuiwop:511 is not listed on IDEAS
    19. Fridolfsson, Sven-Olof & Stennek, Johan, 2000. "Why Event Studies Do Not Detect Anti-Competitive Mergers," Working Paper Series 542, Research Institute of Industrial Economics.
    20. Szidarovszky, F. & Yakowitz, S., 1982. "Contributions to Cournot oligopoly theory," Journal of Economic Theory, Elsevier, vol. 28(1), pages 51-70, October.
    21. Houston, Joel F. & Ryngaert, Michael D., 1994. "The overall gains from large bank mergers," Journal of Banking & Finance, Elsevier, vol. 18(6), pages 1155-1176, December.
    22. Shleifer, Andrei & Vishny, Robert W, 1988. "Value Maximization and the Acquisition Process," Journal of Economic Perspectives, American Economic Association, vol. 2(1), pages 7-20, Winter.
    23. Jensen, Michael C. & Ruback, Richard S., 1983. "The market for corporate control : The scientific evidence," Journal of Financial Economics, Elsevier, vol. 11(1-4), pages 5-50, April.
    24. Berkovitch, Elazar & Narayanan, M. P., 1993. "Motives for Takeovers: An Empirical Investigation," Journal of Financial and Quantitative Analysis, Cambridge University Press, vol. 28(03), pages 347-362, September.
    25. Kamien, Morton I & Zang, Israel, 1993. "Monopolization by Sequential Acquisition," Journal of Law, Economics, and Organization, Oxford University Press, vol. 9(2), pages 205-229, October.
    26. Drew Fudenberg & Jean Tirole, 1985. "Preemption and Rent Equalization in the Adoption of New Technology," Review of Economic Studies, Oxford University Press, vol. 52(3), pages 383-401.
    27. Ajeyo Banerjee & E. Woodrow Eckard, 1998. "Are Mega-Mergers Anticompetitive? Evidence from the First Great Merger Wave," RAND Journal of Economics, The RAND Corporation, vol. 29(4), pages 803-827, Winter.
    28. Fudenberg, Drew & Gilbert, Richard & Stiglitz, Joseph & Tirole, Jean, 1983. "Preemption, leapfrogging and competition in patent races," European Economic Review, Elsevier, vol. 22(1), pages 3-31, June.
    29. repec:hhs:iuiwop:542 is not listed on IDEAS
    30. James D. Reitzes & David T. Levy, 1995. "Price Discrimination and Mergers," Canadian Journal of Economics, Canadian Economics Association, vol. 28(2), pages 427-436, May.
    31. Raghavendra Rau, P. & Vermaelen, Theo, 1998. "Glamour, value and the post-acquisition performance of acquiring firms," Journal of Financial Economics, Elsevier, vol. 49(2), pages 223-253, August.
    32. Mark Bagnoli, Barton L. Lipman, 1988. "Successful Takeovers without Exclusion," Review of Financial Studies, Society for Financial Studies, vol. 1(1), pages 89-110.
    33. Raymond Deneckere & Carl Davidson, 1985. "Incentives to Form Coalitions with Bertrand Competition," RAND Journal of Economics, The RAND Corporation, vol. 16(4), pages 473-486, Winter.
    Full references (including those not matched with items on IDEAS)

    More about this item


    Mergers; Acquisitions; Defensive Mergers; Coalition Formation;

    JEL classification:

    • L13 - Industrial Organization - - Market Structure, Firm Strategy, and Market Performance - - - Oligopoly and Other Imperfect Markets
    • L41 - Industrial Organization - - Antitrust Issues and Policies - - - Monopolization; Horizontal Anticompetitive Practices
    • G34 - Financial Economics - - Corporate Finance and Governance - - - Mergers; Acquisitions; Restructuring; Corporate Governance
    • C78 - Mathematical and Quantitative Methods - - Game Theory and Bargaining Theory - - - Bargaining Theory; Matching Theory


    Access and download statistics


    All material on this site has been provided by the respective publishers and authors. You can help correct errors and omissions. When requesting a correction, please mention this item's handle: RePEc:wzb:wzebiv:fsiv01-26. See general information about how to correct material in RePEc.

    For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: (Jennifer Rontganger). General contact details of provider: .

    If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

    If CitEc recognized a reference but did not link an item in RePEc to it, you can help with this form .

    If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your RePEc Author Service profile, as there may be some citations waiting for confirmation.

    Please note that corrections may take a couple of weeks to filter through the various RePEc services.

    IDEAS is a RePEc service hosted by the Research Division of the Federal Reserve Bank of St. Louis . RePEc uses bibliographic data supplied by the respective publishers.