The European Journal of Health Economics

, Volume 17, Issue 8, pp 1027–1040 | Cite as

The diffusion of generics after patent expiry in Germany

  • Katharina Elisabeth FischerEmail author
  • Tom Stargardt
Original Paper


To identify the influences on the diffusion of generics after patent expiry, we analyzed 65 generic entries using prescription data of a large German sickness fund between 2007 and 2012 in a sales model. According to theory, several elements are responsible for technology diffusion: (1) time reflecting the rate of adaption within the social system, (2) communication channels, and (3) the degree of incremental innovation, e.g., the modifications of existing active ingredient’s strength. We investigated diffusion in two ways: (1) generic market share (percentage of generic prescriptions of all prescriptions of a substance) and, (2) generic sales quantity (number of units sold) over time. We specified mixed regression models. Generic diffusion takes considerable time. An average generic market share of about 75 % was achieved not until 48 months. There was a positive effect of time since generic entry on generic market share (p < 0.001) and sales (p < 0.001). Variables describing the communication channels and the degree of innovation influenced generic market share (mostly p < 0.001), but not generic sales quantity. Market structure, e.g., the number of generic manufacturers (p < 0.001) and prices influenced both generic market share and sales. Imperfections in generic uptake through informational cascades seem to be largely present. Third-party payers could enhance means to promote generic diffusion to amplify savings through generic entry.


Pharmaceutical industry Market regulation Off-patent markets Product life cycle Generic entry Generic market share 

JEL Classification




This study was supported by a research grant from the Federal Ministry of Education and Research in Germany (Grant number BMBF 01EH1101A).

Compliance with ethical standards

Conflict of interest

The author(s) declare that they have no competing interests.

Supplementary material

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Supplementary material 1 (PDF 373 kb)
10198_2015_744_MOESM2_ESM.pdf (2.1 mb)
Supplementary material 2 (PDF 2177 kb)


  1. 1.
    Danzon, P.M., Furukawa, M.F.: Cross-national evidence on generic pharmaceuticals: pharmacy vs. physician-driven markets. NBER working paper 17226. (2011)
  2. 2.
    Dunne, S., Shannon, B., Dunne, C., Cullen, W.: A review of the differences and similarities between generic drugs and their originator counterparts, including economic benefits associated with usage of generic medicines, using Ireland as a case study. BMC Pharmacol. Toxicol. 5(14), 1 (2013)CrossRefGoogle Scholar
  3. 3.
    Rischatsch, M., Trottmann, M., Zweifel, P.: Generic substitution, financial interests, and imperfect agency. Int. J. Health Care Finance Econ. 13(2), 115–138 (2013)CrossRefPubMedGoogle Scholar
  4. 4.
    Duflos, G., Lichtenberg, F.R.: Does competition stimulate drug utilization? The impact of changes in market structure on US drug prices, marketing and utilization. Int. Rev. Law Econ. 32(1), 95–109 (2012)CrossRefGoogle Scholar
  5. 5.
    Kanavos, P., Costa-Font, J., Seeley, E.: Competition in off-patent drug markets: issues, regulation and evidence. Econ. Policy 23(55), 499–544 (2008)CrossRefGoogle Scholar
  6. 6.
    Kesselheim, A.S.: Clinical equivalence of generic and brand-name drugs used in cardiovascular disease: a systematic review and meta-analysis. JAMA 300(21), 2514 (2008)CrossRefPubMedPubMedCentralGoogle Scholar
  7. 7.
    Vogler, S.: The impact of pharmaceutical pricing and reimbursement policies on generics uptake: implementation of policy options on generics in 29 European countries—an overview. Generics Biosimilars Initiat. J. 1(2), 93–100 (2012)CrossRefGoogle Scholar
  8. 8.
    Shrank, W.H., Choudhry, N.K., Agnew-Blais, J., Federman, A.D., Liberman, J.N., Liu, J., et al.: State generic substitution laws can lower drug outlays under Medicaid. Health Aff. 29(7), 1383–1390 (2010)CrossRefGoogle Scholar
  9. 9.
    Stargardt, T., Vandoros, S.: Pharmaceutical pricing and reimbursement regulation in Europe. In: Culyer, A.J. (ed.) Encyclopedia of Health Economics, pp. 29–36. Elsevier, San Diego (2014)CrossRefGoogle Scholar
  10. 10.
    Schreyögg, J., Busse, R.: Drug budgets and effects on physicians’ prescription behaviour: new evidence from Germany. J. Pharm. Finance Econ. Policy 14(3), 77–95 (2005)CrossRefGoogle Scholar
  11. 11.
    Stargardt, T.: The impact of reference pricing on switching behaviour and healthcare utilisation: the case of statins in Germany. Eur. J. Health Econ. 11(3), 267–277 (2010)CrossRefPubMedGoogle Scholar
  12. 12.
    Stargardt, T., Busse, R., Dauben, H.-P.: Germany—pharma profile—pharmaceutical pricing and reimbursement information. WHO Regional Office for Europe (2008) [cited 2012 Nov 19]. Available from
  13. 13.
    Vandoros, S.: Therapeutic substitution post-patent expiry: the cases of ace inhibitors and proton pump inhibitors. Health Econ. 23(5), 621–630 (2014)CrossRefPubMedGoogle Scholar
  14. 14.
    Ching, A.T.: A dynamic oligopoly structural model for the prescription drug market after patent expiration*. Int. Econ. Rev. 51(4), 1175–1207 (2010)CrossRefGoogle Scholar
  15. 15.
    Decollogny, A., Eggli, Y., Halfon, P., Lufkin, T.M.: Determinants of generic drug substitution in Switzerland. BMC Health Serv. Res. 11(1), 17 (2011)CrossRefPubMedPubMedCentralGoogle Scholar
  16. 16.
    Hellström, J., Rudholm, N.: Uncertainty in the generic versus brand name prescription decision. Empir. Econ. 38(3), 503–521 (2010)CrossRefGoogle Scholar
  17. 17.
    Costa-Font, J., Rudisill, C., Tan, S.: Brand loyalty, patients and limited generic medicines uptake. Health Policy 116(2–3), 224–233 (2014)CrossRefPubMedGoogle Scholar
  18. 18.
    Boersma, C., Klok, R.M., Bos, J.M., Naunton, M., van den Berg, P.B., Postma, M.J., et al.: Drug costs developments after patent expiry of enalapril, fluoxetine and ranitidine. Appl. Health Econ. Health Policy 4(3), 191–196 (2005)CrossRefPubMedGoogle Scholar
  19. 19.
    Moreno-Torres, I., Puig-Junoy, J., Borrell, J.-R.: Generic entry into the regulated Spanish pharmaceutical market. Rev. Ind. Organ. 34(4), 373–388 (2009)CrossRefGoogle Scholar
  20. 20.
    Costa-Font, J., McGuire, A., Varol, N.: Price regulation and relative delays in generic drug adoption. J. Health Econ. 38, 1–9 (2014)CrossRefPubMedGoogle Scholar
  21. 21.
    Frank, R.G., Salkever, D.S.: Generic entry and the pricing of pharmaceuticals. J. Econ. Manag. Strategy 6(1), 75–90 (1997)CrossRefGoogle Scholar
  22. 22.
    Caves, R.E., Whinston, M.D., Hurwitz, M.A., Pakes, A., Temin, P.: Patent expiration, entry, and competition in the US pharmaceutical industry. Brookings papers on economic activity. Microeconomics. 1991, 1–66 (1991)Google Scholar
  23. 23.
    Grabowski, H.G., Vernon, J.M.: Brand loyalty, entry, and price competition in pharmaceuticals after the 1984 Drug Act. J. Law Econ. 35(2), 331–350 (1992)CrossRefGoogle Scholar
  24. 24.
    Gonzalez, J., Sismeiro, C., Dutta, S., Stern, P.: Can branded drugs benefit from generic entry? The role of detailing and price in switching to non-bioequivalent molecules. Int. J. Res. Mark. 25(4), 247–260 (2008)CrossRefGoogle Scholar
  25. 25.
    Puig-Junoy, J., Moreno-Torres, I.: Do generic firms and the Spanish public purchaser respond to consumer price differences of generics under reference pricing? Health Policy 98(2–3), 186–194 (2010)CrossRefPubMedGoogle Scholar
  26. 26.
    Vandoros, S., Kanavos, P.: The generics paradox revisited: empirical evidence from regulated markets. Appl. Econ. 45(22), 3230–3239 (2013)CrossRefGoogle Scholar
  27. 27.
    Magazzini, L., Pammolli, F., Riccaboni, M.: Dynamic competition in pharmaceuticals. HEPAC 5(2), 175–182 (2004)PubMedGoogle Scholar
  28. 28.
    Pechlivanoglou, P., van der Veen, W., Bos, J., Postma, M.: Analyzing generic and branded substitution patterns in the Netherlands using prescription data. BMC Health Serv. Res. 11(1), 89 (2011)CrossRefPubMedPubMedCentralGoogle Scholar
  29. 29.
    Bass, F.M.: A new product growth for model consumer durables. Manag. Sci. 15(5), 215–227 (1969)CrossRefGoogle Scholar
  30. 30.
    Peres, R., Muller, E., Mahajan, V.: Innovation diffusion and new product growth models: a critical review and research directions. Int. J. Res. Mark. 27(2), 91–106 (2010)CrossRefGoogle Scholar
  31. 31.
    Ruiz-Conde, E., Wieringa, J.E., Leeflang, P.S.H.: Competitive diffusion of new prescription drugs: the role of pharmaceutical marketing investment. Technol. Forecast. Soc. Chang. 88, 49–63 (2014)CrossRefGoogle Scholar
  32. 32.
    Landsman, V., Verniers, I., Stremersch, S., Gopalakrishnan, A.: Portfolio management in new drug development. In: Ding, M., Eliashberg, J., Stremersch, S. (eds.) The Successful Launch and Diffusion of New Therapies, pp. 189–223. Springer, New York (2015). doi: 10.1007/978-1-4614-7801-0_3 Google Scholar
  33. 33.
    Stremersch, S., Lemmens, A.: Sales growth of new pharmaceuticals across the globe: the role of regulatory regimes. Mark. Sci. 28(4), 690–708 (2009)CrossRefGoogle Scholar
  34. 34.
    OECD. OECD health data: pharmaceutical market [Internet]. doi: 10.1787/health-data-en (2015). Available from
  35. 35.
    ProGenerika E.V.: PRESSE [Internet] [cited 2014 Feb 6]. Available from
  36. 36.
    Hauser, J., Tellis, G.J., Griffin, A.: Research on innovation: a review and agenda for marketing science. Mark. Sci. 25(6), 687–717 (2006)CrossRefGoogle Scholar
  37. 37.
    Rogers, E.M.: Diffusion of innovations, 5th edn. Free Press, New York [u.a.] (2003)Google Scholar
  38. 38.
    Mahajan, V., Muller, E., Bass, F.M.: New product diffusion models in marketing: a review and directions for research. J. Mark. 54(1), 1–26 (1990)CrossRefGoogle Scholar
  39. 39.
    Golder, P.N., Tellis, G.J.: Growing, growing, gone: cascades, diffusion, and turning points in the product life cycle. Mark. Sci. 23(2), 207–218 (2004)CrossRefGoogle Scholar
  40. 40.
    Coleman, J.S., Katz, E., Menzel, H.: Medical innovation: a diffusion study. Bobbs-Merrill, Indianapolis [u.a.] (1966)Google Scholar
  41. 41.
    Ding, M., Ding, M., Eliashberg, J., Stremersch, S., Stremersch, S.: The pharmaceutical industry: specificity, challenges, and what you can learn from this book. In: Ding, M., Eliashberg, J., Stremersch, S. (eds.) Innovation and Marketing in the Pharmaceutical Industry, pp. 1–18. New York, Springer (2014). doi: 10.1007/978-1-4614-7801-0_1 CrossRefGoogle Scholar
  42. 42.
    Leeflang, P.S.H., Wieringa, J.E.: Modeling the effects of pharmaceutical marketing. Mark. Lett. 21(2), 121–133 (2010)CrossRefGoogle Scholar
  43. 43.
    Lakdawalla, D., Philipson, T., Wang, Y.R.: Intellectual property and marketing [Internet]. National Bureau of Economic Research, Cambridge, MA. Report No.: w12577 (2006 Oct). Available from
  44. 44.
    Bae, J.P.: Drug patent expirations and the speed of generic entry. Health Serv. Res. 32(1), 87–101 (1997)PubMedPubMedCentralGoogle Scholar
  45. 45.
    Banbury, C.M., Mitchell, W.: The effect of introducing important incremental innovations on market share and business survival. Strategy Manag. J. 16(S1), 161–182 (1995)CrossRefGoogle Scholar
  46. 46.
    Barei, F., Le Pen, C., Simoens, S.: The generic pharmaceutical industry: moving beyond incremental innovation towards re-innovation. GaBI J. 2013(1), 13–19 (2013)CrossRefGoogle Scholar
  47. 47.
    Ellison, G., Ellison, S.F.: Strategic entry deterrence and the behavior of pharmaceutical incumbents prior to patent expiration. Am. Econ. J. Microecon. 3(1), 1–36 (2011)CrossRefGoogle Scholar
  48. 48.
    Regan, T.L.: Generic entry, price competition, and market segmentation in the prescription drug market. Int. J. Ind. Organ. 26(4), 930–948 (2008)CrossRefGoogle Scholar
  49. 49.
    German Institute of Medical Documentation and Information: ATC-classification with defined daily doses [Internet] (2014). Available from
  50. 50.
    Hunger, M., Döring, A., Holle, R.: Longitudinal beta regression models for analyzing health-related quality of life scores over time. BMC Med. Res. Methodol. 12(1), 144 (2012)CrossRefPubMedPubMedCentralGoogle Scholar
  51. 51.
    Verkuilen, J., Smithson, M.: Mixed and Mixture Regression Models for Continuous Bounded Responses Using the Beta Distribution. J. Educ. Behav. Stat. 37(1), 82–113 (2012)CrossRefGoogle Scholar
  52. 52.
    Wooldridge, J.M.: Econometric analysis of cross section and panel data. The MIT press, Cambridge (2002) [cited 2013 Sep 5]. Available from
  53. 53.
    Fitzmaurice, G.M.: Applied longitudinal analysis, 2nd edn. Wiley, Hoboken (2011)Google Scholar
  54. 54.
    Ballinger, G.A.: Using generalized estimating equations for longitudinal data analysis. Organ. Res. Methods 7(2), 127–150 (2004)CrossRefGoogle Scholar
  55. 55.
    Blume, H., Brauer, K., Dingermann, T., Mutschler, E., Steinhilber, D., Abdel-Tawab, M., et al.: Gute Substitutionspraxis Leitlinie [Good substitution guidance]. Deutsche Pharmazeutische Gesellschaft e.V. (2014)Google Scholar
  56. 56.
    Talukdar, D., Sudhir, K., Ainslie, A.: Investigating new product diffusion across products and countries. Mark. Sci. 21(1), 97–114 (2002)CrossRefGoogle Scholar
  57. 57.
    Fischer, M., Leeflang, P.S.H., Verhoef, P.C.: Drivers of peak sales for pharmaceutical brands. Quant. Mark. Econ. 8(4), 429–460 (2010)CrossRefGoogle Scholar
  58. 58.
    Vakratsas, D., Kolsarici, C.: A dual-market diffusion model for a new prescription pharmaceutical. Int. J. Res. Mark. 25(4), 282–293 (2008)CrossRefGoogle Scholar
  59. 59.
    Shrank, W.H., Liberman, J.N., Fischer, M.A., Girdish, C., Brennan, T.A., Choudhry, N.K.: Physician perceptions about generic drugs. Ann. Pharmacother. 45(1), 31–38 (2011)CrossRefPubMedGoogle Scholar
  60. 60.
    Papageorgiou, L.G., Rotstein, G.E., Shah, N.: Strategic supply chain optimization for the pharmaceutical industries. Ind. Eng. Chem. Res. 40(1), 275–286 (2001)CrossRefGoogle Scholar
  61. 61.
    Lam, K.D., Miao, Y., Steinman, M.A.: Cumulative changes in the use of chronic medications: a measure of prescribing complexity. JAMA Int. Med. 173(16), 1546–1547 (2013)CrossRefGoogle Scholar
  62. 62.
    Hong, S.H., Shepherd, M.D., Scoones, D., Wan, T.T.: Product-line extensions and pricing strategies of brand-name drugs facing patent expiration [Internet]. JMCP 11(9). Available from Cited 2013 Aug 6 (2005)
  63. 63.
    Huckfeldt, P., Knittel, C.: Pharmaceutical use following generic entry: paying less and buying less [Internet] (2012) [cited 2013 May 29]. Available from
  64. 64.
    Berndt, E.R., Mortimer, R., Bhattacharjya, A., Parece, A., Tuttle, E.: Authorized generic drugs, price competition and consumers’ welfare. Health Aff. 26(3), 790–799 (2007)CrossRefGoogle Scholar
  65. 65.
    Aronsson, T., Bergman, M.A., Rudholm, N.: The impact of generic drug competition on brand name market shares–evidence from micro data. Rev. Ind. Organ. 19(4), 423–433 (2001)CrossRefGoogle Scholar
  66. 66.
    Opocher, A., Steedman, I.: The industry supply curve: two different traditions. Eur. J. Hist. Econ. Thought 15(2), 247–274 (2008)CrossRefGoogle Scholar
  67. 67.
    Moon, J.C., Godman, B., Petzold, M., Alvarez-Madrazo, S., Bennett, K., Bishop, I., et al.: Different initiatives across Europe to enhance losartan utilization post generics: impact and implications. Front Pharmacol. [Internet] 5 (2014) [cited 27 Nov 2014]. Available from
  68. 68.
    Federal Joint Committee. Beschluss des Gemeinsamen Bundesausschusses über eine Änderung der Arzneimittel-Richtlinie (AM-RL): Abschnitt M und Anlage VII - Hinweise zur Austauschbarkeit von Darreichungsformen (aut idem) gemäß §129 Absatz 1a SGB V - Bestimmung von Arzneimitteln, deren Ersetzung durch ein wirkstoffgleiches Arzneimittel ausgeschlossen ist (1. Tranche) [Internet] (2014) [cited 2014 Oct 16]. Available from

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© Springer-Verlag Berlin Heidelberg 2015

Authors and Affiliations

  1. 1.Hamburg Center for Health EconomicsUniversität HamburgHamburgGermany

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