nep-ind New Economics Papers
on Industrial Organization
Issue of 2026–03–23
seven papers chosen by
Kwang Soo Cheong, Johns Hopkins University


  1. Perfect competition and increasing returns A partial equilibrium analysis By Dehez, Pierre; Drèze, Jacques
  2. Questioning the Digital Markets Act's Legality By Thibault Schrepel; Godefroy de Boiscuillé
  3. Lobbying for Regulations: When Big Business Says Yes By Luca Macedoni; Ariel Weinberger
  4. How Does Tort Reform Affect Health Care Delivery By Courtemanche, Charles; Garuccio, Joseph
  5. Competition in Health Insurance Markets By Martin Gaynor; Amanda Starc
  6. Physician Competition: Entry and Substitution By Joshua D. Gottlieb; Sean Nicholson
  7. Beyond the Discount War: Strategy and Survival in India’s Food Delivery Duopoly By Tarush, Akshat

  1. By: Dehez, Pierre (Université catholique de Louvain, LIDAM/CORE, Belgium); Drèze, Jacques (Université catholique de Louvain, LIDAM/CORE, Belgium)
    Abstract: The purpose of the present paper is to challenge the standard textbook analysis of perfect competition based on profit maximisation and the associated "price equal marginal cost" rule leading to an increasing market supply curve.
    Keywords: Competitive equilibrium ; increasing returns to scale ; pricing rule
    JEL: D21 D41
    Date: 2026–01–01
    URL: https://d.repec.org/n?u=RePEc:cor:louvco:2026002
  2. By: Thibault Schrepel (Vrije Universiteit Amsterdam, Netherlands); Godefroy de Boiscuillé (Université Côte d'Azur, CNRS, GREDEG, France)
    Abstract: This article questions the legal validity of the Digital Markets Act ("DMA") in light of its enforcement practice. Adopted on the basis of Article 114 TFEU as an internal market harmonization measure, the DMA is administered by the Commission as a standing regime of unilateral conduct control that operates alongside, and in close normative proximity to, Article 102 TFEU. The resulting functional equivalence between the two instruments raises structural doubts as to the DMA's compatibility with the constitutional framework of the Treaties.
    Keywords: Digital Markets Act; Article 102 TFEU; European Union law; Competition law; Digital platforms; Gatekeepers
    JEL: K21 K23 L40 L86
    Date: 2026–03
    URL: https://d.repec.org/n?u=RePEc:gre:wpaper:2026-07
  3. By: Luca Macedoni; Ariel Weinberger
    Abstract: Do firms uniformly oppose regulations that increase production costs, or might industry leaders strategically support stricter standards as a competitive tool? We identify a specific mechanism through which large firms strategically support regulations to enhance their competitive position. Extending the Melitz-Chaney model of firm heterogeneity to incorporate government regulations and lobbying following Grossman-Helpman, we derive conditions under which regulations disproportionately burden smaller competitors while benefiting larger survivors through reduced competition. The model predicts that firm size is positively correlated with support for stringent regulations, but that larger sunk investments push firms to oppose such policies. To test these predictions, we develop a text-as-data approach using large language models to classify firm regulatory preferences from lobbying disclosures—a measurement challenge that has limited prior systematic analysis. Applying guided machine learning to over 20, 000 U.S. lobbying reports, we confirm that larger firms are significantly more likely to support stricter regulations, especially in concentrated industries. Capital-intensive firms with high leverage and less redeployable assets tend to oppose regulations, suggesting that operational flexibility is crucial for extracting strategic benefits from regulatory changes.
    Keywords: strategic lobbying, product standard regulations, firm heterogeneity, machine learning
    JEL: F12 D22 D72 L11 L51
    Date: 2026
    URL: https://d.repec.org/n?u=RePEc:ces:ceswps:_12536
  4. By: Courtemanche, Charles (University of Kentucky); Garuccio, Joseph (University of Kentucky)
    Abstract: Health care costs in the U.S. have grown dramatically over the past several decades, with one possible cause being physicians providing unnecessary services out of fear of being sued for malpractice – a phenomenon known as “defensive medicine†. States responded by enacting different types of tort reforms. This paper reviews the literature on the effects of these reforms on outcomes related to malpractice risk, quantity and quality of health care services, overall utilization and expenditures, physician supply, and patient affordability. We use Google Scholar to identify papers within this scope and use either associational or quasi-experimental quantitative methods. The preponderance of evidence points towards non-economic damage caps reducing malpractice risk, quantity of services (aside from diagnostics and obstetrics), and overall health care utilization and expenditures while increasing physician supply and not having detrimental effects on patient outcomes. In general, the effects of other types of reforms are less clear. The literature would benefit from further research utilizing methodological advances related to combining machine learning with causal inference and eliminating bias from heterogeneous treatment effects.
    Keywords: tort reform, defensive medicine, physicians, hospitals, health care regulation
    JEL: I11 I18 K13 L25 L51
    Date: 2026–03
    URL: https://d.repec.org/n?u=RePEc:iza:izadps:dp18455
  5. By: Martin Gaynor; Amanda Starc
    Abstract: The United States relies primarily on private health insurance markets, yet these markets are highly concentrated and becoming more so over time. We document concentration across commercial, Medicare Advantage, and Medicaid markets. We then examine how asymmetric information—particularly adverse selection—interacts with market power to shape premiums, plan design, and consumer welfare. Empirical evidence confirms that insurer consolidation raises premiums. We discuss how antitrust enforcement, risk adjustment, regulation, and informational interventions shape competition and consumer welfare in these markets.
    JEL: I11
    Date: 2026–03
    URL: https://d.repec.org/n?u=RePEc:nbr:nberwo:34928
  6. By: Joshua D. Gottlieb; Sean Nicholson
    Abstract: We describe competition in the physician market, focusing on how entry barriers and substitution possibilities have changed in recent decades. Regulatory caps on medical school seats and residency slots—especially for high-paying specialties—continue to ration entry, generate high returns for those who gain these slots, and direct the most academically accomplished trainees toward lucrative fields. But trained physicians increasingly compete with nurse practitioners, physician assistants, and other mid-level practitioners in the market for patients. Training of these substitutes has expanded far more rapidly than physician supply. We present key facts about the physician pipeline, a conceptual framework linking specialty earnings to entry barriers, and describe the rise of mid-level providers. These facts mean that effective competition policy in physician markets must look beyond conventional concentration measures and focus on the institutions and laws that govern who can provide medical care.
    JEL: I11 J44 L13 L50
    Date: 2026–03
    URL: https://d.repec.org/n?u=RePEc:nbr:nberwo:34955
  7. By: Tarush, Akshat (Daikin India)
    Abstract: India’s online food delivery market has consolidated into a stable duopoly following the exits of Uber Eats and Amazon Food. Standard Bertrand competition predicts that such a market structure should result in aggressive price discounting and persistent margin erosion. However, the observed trajectory of Zomato and Swiggy diverges from this prediction. This paper argues that the Indian food delivery duopoly is better understood through the framework of Nash equilibrium and repeated game theory rather than static price competition. Drawing on financial disclosures, regulatory developments and strategic investments across adjacent verticals, the analysis shows that both firms have shifted capital allocation toward quick commerce and dining and entertainment services. These investments reduce direct confrontation in the core food delivery segment and function as a structural analogue to mixed strategy behavior. Instead of committing exclusively to price based competition, each firm distributes resources across multiple business lines, generating strategic unpredictability and limiting profitable unilateral deviation. The stability of this equilibrium is reinforced by public market discipline that constrains explicit coordination while allowing tacit adjustment. The paper contributes to the understanding of platform competition in emerging digital markets by demonstrating how vertical differentiation can stabilize outcomes in environments where pure price rivalry would otherwise destroy value.
    Date: 2026–03–03
    URL: https://d.repec.org/n?u=RePEc:osf:socarx:4m7yr_v1

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