IDEAS home Printed from https://ideas.repec.org/a/the/publsh/6468.html

Choice or competition: does integration benefit everyone?

Author

Listed:
  • Kamada, Yuichiro

    (Haas School of Business, University of California, Berkeley and Department of Economics, University of Tokyo)

  • Kojima, Fuhito

    (Department of Economics, University of Tokyo)

Abstract

Matching markets are often fragmented, organized at a small local level. While integration of matching markets may lead to welfare gains by expanding choice, it may also harm some market participants by increasing competition for the same resources. We show that every "good" mechanism fails the monotonicity requirement that no individuals be hurt by integration. Then we provide characterization results that identify conditions under which monotonicity becomes compatible with other desirable properties of matching mechanisms.

Suggested Citation

  • Kamada, Yuichiro & Kojima, Fuhito, 2026. "Choice or competition: does integration benefit everyone?," Theoretical Economics, Econometric Society, vol. 21(1), January.
    • Handle: RePEc:the:publsh:6468
    as

    Download full text from publisher

    File URL: http://econtheory.org/ojs/index.php/te/article/viewFile/20260001/44182/1344
    Download Restriction: no
    ---><---

    References listed on IDEAS

    as
    1. Vincent W. Slaugh & Mustafa Akan & Onur Kesten & M. Utku Ünver, 2016. "The Pennsylvania Adoption Exchange Improves Its Matching Process," Interfaces, INFORMS, vol. 46(2), pages 133-153, April.
    2. Fuhito Kojima & Mihai Manea, 2010. "Axioms for Deferred Acceptance," Econometrica, Econometric Society, vol. 78(2), pages 633-653, March.
    3. Roth, Alvin E, 1984. "The Evolution of the Labor Market for Medical Interns and Residents: A Case Study in Game Theory," Journal of Political Economy, University of Chicago Press, vol. 92(6), pages 991-1016, December.
    4. Kesten, Onur, 2006. "On two competing mechanisms for priority-based allocation problems," Journal of Economic Theory, Elsevier, vol. 127(1), pages 155-171, March.
    5. Gersbach, Hans & Haller, Hans, 2022. "Gainers and losers from market integration," Mathematical Social Sciences, Elsevier, vol. 116(C), pages 32-39.
    6. Muntasir Chaudhury & Szilvia Papai, 2024. "Affirmative Action Policies in School Choice: Immediate versus Deferred Acceptance," Working Papers 24001, Concordia University, Department of Economics.
    7. Roth, Alvin E., 1985. "The college admissions problem is not equivalent to the marriage problem," Journal of Economic Theory, Elsevier, vol. 36(2), pages 277-288, August.
    8. Alexander Westkamp, 2013. "An analysis of the German university admissions system," Economic Theory, Springer;Society for the Advancement of Economic Theory (SAET), vol. 53(3), pages 561-589, August.
    9. Kamada, Yuichiro & Kojima, Fuhito, 2018. "Stability and strategy-proofness for matching with constraints: a necessary and sufficient condition," Theoretical Economics, Econometric Society, vol. 13(2), May.
    10. Kojima, Fuhito & Tamura, Akihisa & Yokoo, Makoto, 2018. "Designing matching mechanisms under constraints: An approach from discrete convex analysis," Journal of Economic Theory, Elsevier, vol. 176(C), pages 803-833.
    Full references (including those not matched with items on IDEAS)

    Most related items

    These are the items that most often cite the same works as this one and are cited by the same works as this one.
    1. Yuichiro Kamada & Fuhito Kojima, 2020. "Accommodating various policy goals in matching with constraints," The Japanese Economic Review, Springer, vol. 71(1), pages 101-133, January.
    2. Elizabeth Nanami Aoi, 2025. "Matching with regional constraints: An equivalence," Papers 2504.17467, arXiv.org.
    3. Akahoshi, Takashi, 2014. "Singleton core in many-to-one matching problems," Mathematical Social Sciences, Elsevier, vol. 72(C), pages 7-13.
    4. Alvin Roth, 2008. "Deferred acceptance algorithms: history, theory, practice, and open questions," International Journal of Game Theory, Springer;Game Theory Society, vol. 36(3), pages 537-569, March.
    5. Federico Echenique & Teddy Mekonnen & M. Bumin Yenmez, 2026. "Distributional Preferences for Market Design," Papers 2602.08035, arXiv.org.
    6. Tomoeda, Kentaro, 2018. "Finding a stable matching under type-specific minimum quotas," Journal of Economic Theory, Elsevier, vol. 176(C), pages 81-117.
    7. Doğan, Battal & Erdil, Aytek, 2025. "Widening access in university admissions," Journal of Economic Theory, Elsevier, vol. 224(C).
    8. Yeon-Koo Che & Jinwoo Kim & Fuhito Kojima, 2019. "Monotone Comparative Statics without Lattices," Papers 1911.06442, arXiv.org, revised Mar 2026.
    9. Schummer, James & Abizada, Azar, 2017. "Incentives in landing slot problems," Journal of Economic Theory, Elsevier, vol. 170(C), pages 29-55.
    10. Orhan Aygun & Bertan Turhan, 2020. "Designing Direct Matching Mechanism for India with Comprehensive Affirmative Action," Papers 2004.13264, arXiv.org, revised Dec 2021.
    11. Klaus, Bettina & Klijn, Flip, 2013. "Local and global consistency properties for student placement," Journal of Mathematical Economics, Elsevier, vol. 49(3), pages 222-229.
    12. Lars Ehlers & Bettina Klaus, 2014. "Strategy-Proofness Makes the Difference: Deferred-Acceptance with Responsive Priorities," Mathematics of Operations Research, INFORMS, vol. 39(4), pages 949-966, November.
    13. Kamada, Yuichiro & Kojima, Fuhito, 2017. "Stability concepts in matching under distributional constraints," Journal of Economic Theory, Elsevier, vol. 168(C), pages 107-142.
    14. Yao Cheng & Jingsheng Yu & Ling Zheng, 2025. "Efficient Major Transition Exchange under Distributional and Dual Priority-respecting Constraints," Papers 2504.12727, arXiv.org, revised Sep 2025.
    15. Mustafa Afacan, 2014. "Fictitious students creation incentives in school choice problems," Economic Theory, Springer;Society for the Advancement of Economic Theory (SAET), vol. 56(3), pages 493-514, August.
    16. Yun Liu, 2017. "On the welfare effects of affirmative actions in school choice," Review of Economic Design, Springer;Society for Economic Design, vol. 21(2), pages 121-151, June.
    17. Bettina Klaus & Flip Klijn, 2007. "Fair and efficient student placement with couples," International Journal of Game Theory, Springer;Game Theory Society, vol. 36(2), pages 177-207, October.
    18. Aygün, Orhan & Turhan, Bertan, 2019. "Matching with Generalized Lexicographic Choice Rules," ISU General Staff Papers 20191101070000, Iowa State University, Department of Economics.
    19. Atila Abdulkadiroglu & Tommy Andersson, 2022. "School Choice," NBER Working Papers 29822, National Bureau of Economic Research, Inc.
    20. Paula Jaramillo & Çaǧatay Kayı & Flip Klijn, 2014. "On the exhaustiveness of truncation and dropping strategies in many-to-many matching markets," Social Choice and Welfare, Springer;The Society for Social Choice and Welfare, vol. 42(4), pages 793-811, April.

    More about this item

    Keywords

    ;
    ;
    ;
    ;
    ;
    ;
    ;
    ;
    ;

    JEL classification:

    • C70 - Mathematical and Quantitative Methods - - Game Theory and Bargaining Theory - - - General
    • C78 - Mathematical and Quantitative Methods - - Game Theory and Bargaining Theory - - - Bargaining Theory; Matching Theory
    • D47 - Microeconomics - - Market Structure, Pricing, and Design - - - Market Design
    • D61 - Microeconomics - - Welfare Economics - - - Allocative Efficiency; Cost-Benefit Analysis
    • D63 - Microeconomics - - Welfare Economics - - - Equity, Justice, Inequality, and Other Normative Criteria and Measurement

    Statistics

    Access and download statistics

    Corrections

    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:the:publsh:6468. See general information about how to correct material in RePEc.

    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 bibliographic 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.

    For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: Editor Theoretical Economics The email address of this maintainer does not seem to be valid anymore. Please ask Editor Theoretical Economics to update the entry or send us the correct address (email available below). General contact details of provider: http://econtheory.org .

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

    IDEAS is a RePEc service. RePEc uses bibliographic data supplied by the respective publishers.