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The impact of cost-sharing on prescription drug demand: evidence from a double-difference regression kink design

Author

Listed:
  • Simona Gamba

    (Universitá Cattolica Del Sacro Cuore)

  • Niklas Jakobsson

    (Karlstad University)

  • Mikael Svensson

    (University of Gothenburg)

Abstract

Pharmaceuticals represent the third-largest expenditure item in health care spending in the OECD countries, and cost growth is around 5% per year in many OECD countries. One possible way to contain the rise in pharmaceutical spending is the use of cost-sharing schemes that makes insured individuals directly bear parts of the cost of a drug. This study estimates the price sensitivity of demand for prescription drugs using data on all prescription drug purchases from a random sample of 400,000 Swedes followed from 2010 to 2013. We use a regression kink design (RKD) by exploiting the kinked Swedish cost-sharing scheme to assess the price elasticity. Further, since the cost-sharing scheme has changed over time, we also use a double-difference RKD to account for potential confounding nonlinearities around the kink. Our results indicate that the standard RKD results are biased and exaggerate the price sensitivity. Our preferred double-difference RKD specifications show no or minor price sensitivity (95% CI price elasticity from − 0.12 to 0.02). The results are similar in several sub-group analyses across age groups, sexes, and income quartiles.

Suggested Citation

  • Simona Gamba & Niklas Jakobsson & Mikael Svensson, 2022. "The impact of cost-sharing on prescription drug demand: evidence from a double-difference regression kink design," The European Journal of Health Economics, Springer;Deutsche Gesellschaft für Gesundheitsökonomie (DGGÖ), vol. 23(9), pages 1591-1599, December.
    • Handle: RePEc:spr:eujhec:v:23:y:2022:i:9:d:10.1007_s10198-022-01446-w
    DOI: 10.1007/s10198-022-01446-w
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    References listed on IDEAS

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    1. Marianne Simonsen & Lars Skipper & Niels Skipper, 2016. "Price Sensitivity of Demand for Prescription Drugs: Exploiting a Regression Kink Design," Journal of Applied Econometrics, John Wiley & Sons, Ltd., vol. 31(2), pages 320-337, March.
    2. Astrid Kiil & Kurt Houlberg, 2014. "How does copayment for health care services affect demand, health and redistribution? A systematic review of the empirical evidence from 1990 to 2011," The European Journal of Health Economics, Springer;Deutsche Gesellschaft für Gesundheitsökonomie (DGGÖ), vol. 15(8), pages 813-828, November.
    3. Camille Landais, 2015. "Assessing the Welfare Effects of Unemployment Benefits Using the Regression Kink Design," American Economic Journal: Economic Policy, American Economic Association, vol. 7(4), pages 243-278, November.
    4. John P. A. Ioannidis & T. D. Stanley & Hristos Doucouliagos, 2017. "The Power of Bias in Economics Research," Economic Journal, Royal Economic Society, vol. 127(605), pages 236-265, October.
    5. David Card & David S. Lee & Zhuan Pei & Andrea Weber, 2015. "Inference on Causal Effects in a Generalized Regression Kink Design," Econometrica, Econometric Society, vol. 83, pages 2453-2483, November.
    6. Aviva Aron-Dine & Liran Einav & Amy Finkelstein, 2013. "The RAND Health Insurance Experiment, Three Decades Later," Journal of Economic Perspectives, American Economic Association, vol. 27(1), pages 197-222, Winter.
    7. Helena Skyt Nielsen & Torben Sørensen & Christopher Taber, 2010. "Estimating the Effect of Student Aid on College Enrollment: Evidence from a Government Grant Policy Reform," NBER Chapters, in: Income Taxation, Trans-Atlantic Public Economics Seminar (TAPES), pages 185-215, National Bureau of Economic Research, Inc.
    8. Amitabh Chandra & Jonathan Gruber & Robin McKnight, 2010. "Patient Cost-Sharing and Hospitalization Offsets in the Elderly," American Economic Review, American Economic Association, vol. 100(1), pages 193-213, March.
    9. Manning, Willard G, et al, 1987. "Health Insurance and the Demand for Medical Care: Evidence from a Randomized Experiment," American Economic Review, American Economic Association, vol. 77(3), pages 251-277, June.
    10. Chandra, Amitabh & Gruber, Jonathan & McKnight, Robin, 2014. "The impact of patient cost-sharing on low-income populations: Evidence from Massachusetts," Journal of Health Economics, Elsevier, vol. 33(C), pages 57-66.
    11. David Card & David S. Lee & Zhuan Pei & Andrea Weber, 2017. "Regression Kink Design: Theory and Practice," Advances in Econometrics, in: Regression Discontinuity Designs, volume 38, pages 341-382, Emerald Group Publishing Limited.
    12. Andrew Gelman & Guido Imbens, 2019. "Why High-Order Polynomials Should Not Be Used in Regression Discontinuity Designs," Journal of Business & Economic Statistics, Taylor & Francis Journals, vol. 37(3), pages 447-456, July.
    13. Michihito Ando, 2017. "How much should we trust regression-kink-design estimates?," Empirical Economics, Springer, vol. 53(3), pages 1287-1322, November.
    14. Amy Finkelstein & Sarah Taubman & Bill Wright & Mira Bernstein & Jonathan Gruber & Joseph P. Newhouse & Heidi Allen & Katherine Baicker, 2012. "The Oregon Health Insurance Experiment: Evidence from the First Year," The Quarterly Journal of Economics, President and Fellows of Harvard College, vol. 127(3), pages 1057-1106.
    15. Liran Einav & Amy Finkelstein, 2018. "Moral Hazard in Health Insurance: What We Know and How We Know It," Journal of the European Economic Association, European Economic Association, vol. 16(4), pages 957-982.
    16. Keeler, Emmett B & Morrow, Daniel T & Newhouse, Joseph P, 1977. "The Demand for Supplementary Health Insurance, or Do Deductibles Matter?," Journal of Political Economy, University of Chicago Press, vol. 85(4), pages 789-801, August.
    17. McCrary, Justin, 2008. "Manipulation of the running variable in the regression discontinuity design: A density test," Journal of Econometrics, Elsevier, vol. 142(2), pages 698-714, February.
    18. Peter Ganong & Simon Jäger, 2018. "A Permutation Test for the Regression Kink Design," Journal of the American Statistical Association, Taylor & Francis Journals, vol. 113(522), pages 494-504, April.
    19. Amitabh Chandra & Evan Flack & Ziad Obermeyer, 2021. "The Health Costs of Cost-Sharing," NBER Working Papers 28439, National Bureau of Economic Research, Inc.
    20. Lindsay M. Sabik & Sabina Ohri Gandhi, 2016. "Copayments and Emergency Department Use Among Adult Medicaid Enrollees," Health Economics, John Wiley & Sons, Ltd., vol. 25(5), pages 529-542, May.
    21. Zweifel, Peter & Manning, Willard G., 2000. "Moral hazard and consumer incentives in health care," Handbook of Health Economics, in: A. J. Culyer & J. P. Newhouse (ed.), Handbook of Health Economics, edition 1, volume 1, chapter 8, pages 409-459, Elsevier.
    22. Katherine Baicker & Dana Goldman, 2011. "Patient Cost-Sharing and Healthcare Spending Growth," Journal of Economic Perspectives, American Economic Association, vol. 25(2), pages 47-68, Spring.
    23. Mikael Svensson & Fredrik Nilsson & Karl Arnberg, 2015. "Reimbursement Decisions for Pharmaceuticals in Sweden: The Impact of Disease Severity and Cost Effectiveness," PharmacoEconomics, Springer, vol. 33(11), pages 1229-1236, November.
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    More about this item

    Keywords

    Cost-sharing; Drug consumption; Health-care; Moral hazard; Regression kink design; Natural experiment;
    All these keywords.

    JEL classification:

    • C33 - Mathematical and Quantitative Methods - - Multiple or Simultaneous Equation Models; Multiple Variables - - - Models with Panel Data; Spatio-temporal Models
    • D12 - Microeconomics - - Household Behavior - - - Consumer Economics: Empirical Analysis
    • I11 - Health, Education, and Welfare - - Health - - - Analysis of Health Care Markets
    • I18 - Health, Education, and Welfare - - Health - - - Government Policy; Regulation; Public Health

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