IDEAS home Printed from https://ideas.repec.org/p/tiu/tiucen/4d692f0e-8577-4392-b413-269be650c250.html
   My bibliography  Save this paper

Cost-Sharing and Drug Pricing Strategies : Introducing Tiered Co-Payments in Reference Price Markets

Author

Listed:
  • Suppliet, Moritz

    (Tilburg University, Center For Economic Research)

  • Herr, Annika

Abstract

Co-payments are a common instrument of health insurers to lower their pharmaceutical expenses and to share costs with consumers, the patients. Tiered drug co-payments, e.g. lower co-payments for generic drugs, incentivize patients to buy certain products and, hence, steer drug consumption patterns. Since 2007, the German Statutory Health Insurance follows an innovative and unique regulation by differentiating drug copayments by the drug's price relative to its reference price. Co-payment exemption thresholds have been introduced in 185 out of 281 therapeutic clusters since 2007. We answer how effective this co-payment exemption policy is in order to reduce overall prices for pharmaceutical products. We analyze prices of all drugs marketed in reference price clusters and being subject to the policy in Germany using quarterly data from January 2007 to October 2010 published by the Federal Association of Statutory Health Insurance Funds in Germany. Wend empirical evidence of differentiated price setting strategies by different rm types ranging from price decreases of -8% to increases of +1.3% (innovators) following the introduction of co-payment exemption threshold. We refer to the latter case as the co-payment paradox. Furthermore, prices of generic and branded generic rms and reference prices tend to converge. The results are robust when we estimate static and dynamic linear panel data models and control for the heterogeneity of active ingredient's clusters, autocorrelation, and heteroscedasticity. Our competition proxies (no. of rms and ratio products/rm in the same market) suggest a signicant negative impact of competition on prices and, thereby, question whether more competition may be an alternative way to lower pharmaceutical prices.
(This abstract was borrowed from another version of this item.)
(This abstract was borrowed from another version of this item.)
(This abstract was borrowed from another version of this i
(This abstract was borrowed from another version of this item.)

Suggested Citation

  • Suppliet, Moritz & Herr, Annika, 2016. "Cost-Sharing and Drug Pricing Strategies : Introducing Tiered Co-Payments in Reference Price Markets," Discussion Paper 2016-040, Tilburg University, Center for Economic Research.
  • Handle: RePEc:tiu:tiucen:4d692f0e-8577-4392-b413-269be650c250
    as

    Download full text from publisher

    File URL: https://pure.uvt.nl/ws/portalfiles/portal/13053399/2016_040.pdf
    Download Restriction: no
    ---><---

    Other versions of this item:

    References listed on IDEAS

    as
    1. Michael Gerfin & Boris Kaiser & Christian Schmid, 2015. "Healthcare Demand in the Presence of Discrete Price Changes," Health Economics, John Wiley & Sons, Ltd., vol. 24(9), pages 1164-1177, September.
    2. Tom Stargardt, 2010. "The impact of reference pricing on switching behaviour and healthcare utilisation: the case of statins in Germany," The European Journal of Health Economics, Springer;Deutsche Gesellschaft für Gesundheitsökonomie (DGGÖ), vol. 11(3), pages 267-277, June.
    3. Hansen, Lars Peter, 1982. "Large Sample Properties of Generalized Method of Moments Estimators," Econometrica, Econometric Society, vol. 50(4), pages 1029-1054, July.
    4. Kaiser, Ulrich & Mendez, Susan J. & Rønde, Thomas & Ullrich, Hannes, 2014. "Regulation of pharmaceutical prices: Evidence from a reference price reform in Denmark," Journal of Health Economics, Elsevier, vol. 36(C), pages 174-187.
    5. Berndt Ernst R. & McGuire Thomas & Newhouse Joseph P., 2011. "A Primer on the Economics of Prescription Pharmaceutical Pricing in Health Insurance Markets," Forum for Health Economics & Policy, De Gruyter, vol. 14(2), pages 1-30, November.
    6. Tom Stargardt, 2011. "Modelling pharmaceutical price changes in Germany: a function of competition and regulation," Applied Economics, Taylor & Francis Journals, vol. 43(29), pages 4515-4526.
    7. Stefan Boes & Michael Gerfin, 2016. "Does Full Insurance Increase the Demand for Health Care?," Health Economics, John Wiley & Sons, Ltd., vol. 25(11), pages 1483-1496, November.
    8. Danzon Patricia M. & Ketcham Jonathan D., 2004. "Reference Pricing of Pharmaceuticals for Medicare: Evidence from Germany, the Netherlands, and New Zealand," Forum for Health Economics & Policy, De Gruyter, vol. 7(1), pages 1-56, January.
    9. Brekke, Kurt R. & Grasdal, Astrid L. & Holms, Tor Helge, 2009. "Regulation and pricing of pharmaceuticals: Reference pricing or price cap regulation?," European Economic Review, Elsevier, vol. 53(2), pages 170-185, February.
    10. Lakdawalla, Darius & Sood, Neeraj & Gu, Qian, 2013. "Pharmaceutical advertising and Medicare Part D," Journal of Health Economics, Elsevier, vol. 32(6), pages 1356-1367.
    11. Boris Augurzky & Silja Göhlmann & Stefan Greß & Jürgen Wasem, 2009. "Effects of the German reference drug program on ex‐factory prices of prescription drugs: a panel data approach," Health Economics, John Wiley & Sons, Ltd., vol. 18(4), pages 421-436, April.
    12. Tomaso Duso & Annika Herr & Moritz Suppliet, 2014. "The Welfare Impact Of Parallel Imports: A Structural Approach Applied To The German Market For Oral Anti‐Diabetics," Health Economics, John Wiley & Sons, Ltd., vol. 23(9), pages 1036-1057, September.
    13. Martin B. Hackmann & Jonathan T. Kolstad & Amanda E. Kowalski, 2015. "Adverse Selection and an Individual Mandate: When Theory Meets Practice," American Economic Review, American Economic Association, vol. 105(3), pages 1030-1066, March.
    14. 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.
    15. Brekke, Kurt R. & Holmas, Tor Helge & Straume, Odd Rune, 2011. "Reference pricing, competition, and pharmaceutical expenditures: Theory and evidence from a natural experiment," Journal of Public Economics, Elsevier, vol. 95(7), pages 624-638.
    16. Haiden A. Huskamp & Richard G. Frank & Kimberly A. McGuigan & Yuting Zhang, 2005. "The Impact of a Three‐Tier Formulary on Demand Response for Prescription Drugs," Journal of Economics & Management Strategy, Wiley Blackwell, vol. 14(3), pages 729-753, September.
    17. Andrew J. Epstein & Jonathan D. Ketcham, 2014. "Information technology and agency in physicians' prescribing decisions," RAND Journal of Economics, RAND Corporation, vol. 45(2), pages 422-448, June.
    18. Y. Richard Wang & Mark V. Pauly, 2005. "Spillover Effects of Restrictive Drug Formularies on Physician Prescribing Behavior: Evidence from Medicaid," Journal of Economics & Management Strategy, Wiley Blackwell, vol. 14(3), pages 755-773, September.
    19. Nina Pavcnik, 2002. "Do Pharmaceutical Prices Respond to Potential Patient Out-of-Pocket Expenses?," RAND Journal of Economics, The RAND Corporation, vol. 33(3), pages 469-487, Autumn.
    20. Stock, James H & Wright, Jonathan H & Yogo, Motohiro, 2002. "A Survey of Weak Instruments and Weak Identification in Generalized Method of Moments," Journal of Business & Economic Statistics, American Statistical Association, vol. 20(4), pages 518-529, October.
    21. Anna Merino, 2000. "The impact of the reference price system on the pharmaceutical market: A theoretical approach," Economics Working Papers 524, Department of Economics and Business, Universitat Pompeu Fabra, revised Jun 2003.
    22. Ferrara, Ida & Missios, Paul, 2012. "Pricing of drugs with heterogeneous health insurance coverage," Journal of Health Economics, Elsevier, vol. 31(2), pages 440-456.
    23. Brekke, Kurt Richard & Holmås, Tor Helge & Straume, Odd Rune, 2013. "Margins and market shares: Pharmacy incentives for generic substitution," European Economic Review, Elsevier, vol. 61(C), pages 116-131.
    24. Puig-Junoy, Jaume, 2007. "The impact of generic reference pricing interventions in the statin market," Health Policy, Elsevier, vol. 84(1), pages 14-29, November.
    25. Ariel Pakes, 2003. "A Reconsideration of Hedonic Price Indexes with an Application to PC's," American Economic Review, American Economic Association, vol. 93(5), pages 1578-1596, December.
    26. Judith K. Hellerstein, 1998. "The Importance of the Physician in the Generic Versus Trade-Name Prescription Decision," RAND Journal of Economics, The RAND Corporation, vol. 29(1), pages 108-136, Spring.
    27. Brekke, Kurt R. & Konigbauer, Ingrid & Straume, Odd Rune, 2007. "Reference pricing of pharmaceuticals," Journal of Health Economics, Elsevier, vol. 26(3), pages 613-642, May.
    28. Dalton, Christina M., 2014. "Estimating demand elasticities using nonlinear pricing," International Journal of Industrial Organization, Elsevier, vol. 37(C), pages 178-191.
    29. Richard G. Frank & David S. Salkever, 1997. "Generic Entry and the Pricing of Pharmaceuticals," Journal of Economics & Management Strategy, Wiley Blackwell, vol. 6(1), pages 75-90, March.
    30. Steven N. Wiggins & Robert Maness, 2004. "Price Competition in Pharmaceuticals: The Case of Anti-infectives," Economic Inquiry, Western Economic Association International, vol. 42(2), pages 247-263, April.
    31. Antonio Cabrales & Sergi Jiménez‐Martín, 2013. "The Determinants Of Pricing In Pharmaceuticals: Are Us Prices Really So High?," Health Economics, John Wiley & Sons, Ltd., vol. 22(11), pages 1377-1397, November.
    32. Gaynor Martin & Li Jian & Vogt William B, 2007. "Substitution, Spending Offsets, and Prescription Drug Benefit Design," Forum for Health Economics & Policy, De Gruyter, vol. 10(2), pages 1-33, July.
    33. Toshiaki Iizuka & Ginger Z. Jin, 2007. "Direct To Consumer Advertising And Prescription Choice," Journal of Industrial Economics, Wiley Blackwell, vol. 55(4), pages 771-771, December.
    34. Ganslandt, Mattias & Maskus, Keith E., 2004. "Parallel imports and the pricing of pharmaceutical products: evidence from the European Union," Journal of Health Economics, Elsevier, vol. 23(5), pages 1035-1057, September.
    35. Arellano, Manuel & Bover, Olympia, 1995. "Another look at the instrumental variable estimation of error-components models," Journal of Econometrics, Elsevier, vol. 68(1), pages 29-51, July.
    36. 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.
    37. Bhattacharya, Jayanta & Vogt, William B, 2003. "A Simple Model of Pharmaceutical Price Dynamics," Journal of Law and Economics, University of Chicago Press, vol. 46(2), pages 599-626, October.
    38. Miraldo, Marisa, 2009. "Reference pricing and firms' pricing strategies," Journal of Health Economics, Elsevier, vol. 28(1), pages 176-197, January.
    39. Carl Rudolf Blankart & Tom Stargardt, 2017. "Preferred supplier contracts in post-patent prescription drug markets," Health Care Management Science, Springer, vol. 20(3), pages 419-432, September.
    40. Jorge Mestre, 2003. "Reference prices: The Spanish way," Investigaciones Economicas, Fundación SEPI, vol. 27(1), pages 125-149, January.
    41. Blundell, Richard & Bond, Stephen, 1998. "Initial conditions and moment restrictions in dynamic panel data models," Journal of Econometrics, Elsevier, vol. 87(1), pages 115-143, August.
    42. NicolasR. Ziebarth, 2010. "Estimating Price Elasticities of Convalescent Care Programmes," Economic Journal, Royal Economic Society, vol. 120(545), pages 816-844, June.
    43. Henry G. Grabowski & Margaret Kyle, 2007. "Generic competition and market exclusivity periods in pharmaceuticals," Managerial and Decision Economics, John Wiley & Sons, Ltd., vol. 28(4-5), pages 491-502.
    44. Liran Einav & Amy Finkelstein & Paul Schrimpf, 2015. "The Response of Drug Expenditure to Nonlinear Contract Design: Evidence from Medicare Part D," The Quarterly Journal of Economics, Oxford University Press, vol. 130(2), pages 841-899.
    45. Patrick Bajari & Jane Cooley Fruehwirth & Kyoo il Kim & Christopher Timmins, 2012. "A Rational Expectations Approach to Hedonic Price Regressions with Time-Varying Unobserved Product Attributes: The Price of Pollution," American Economic Review, American Economic Association, vol. 102(5), pages 1898-1926, August.
    46. Lakdawalla, Darius & Sood, Neeraj, 2013. "Health insurance as a two-part pricing contract," Journal of Public Economics, Elsevier, vol. 102(C), pages 1-12.
    47. Regan, Tracy L., 2008. "Generic entry, price competition, and market segmentation in the prescription drug market," International Journal of Industrial Organization, Elsevier, vol. 26(4), pages 930-948, July.
    48. 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.
    49. Danzon, Patricia M. & Chao, Li-Wei, 2000. "Cross-national price differences for pharmaceuticals: how large, and why?," Journal of Health Economics, Elsevier, vol. 19(2), pages 159-195, March.
    50. Grabowski, Henry G & Vernon, John M, 1992. "Brand Loyalty, Entry, and Price Competition in Pharmaceuticals after the 1984 Drug Act," Journal of Law and Economics, University of Chicago Press, vol. 35(2), pages 331-350, October.
    51. 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.
    52. Anna Merino, 2000. "The impact of the reference price system on the pharmaceutical market: A theoretical approach," Working Papers, Research Center on Health and Economics 524, Department of Economics and Business, Universitat Pompeu Fabra, revised Jun 2003.
    53. Ferrara, Ida & Kong, Ying, 2008. "Can health insurance coverage explain the generic competition paradox?," Economics Letters, Elsevier, vol. 101(1), pages 48-52, October.
    54. Mark G. Duggan & Fiona Scott Morton, 2011. "The Medium-Term Impact of Medicare Part D on Pharmaceutical Prices," American Economic Review, American Economic Association, vol. 101(3), pages 387-392, May.
    55. Herr, Annika & Stühmeier, Torben & Wenzel, Tobias, 2014. "Reference pricing and cost-sharing: Theory and evidence on German off-patent drugs," VfS Annual Conference 2014 (Hamburg): Evidence-based Economic Policy 100556, Verein für Socialpolitik / German Economic Association.
    56. Margaret K. Kyle, 2007. "Pharmaceutical Price Controls and Entry Strategies," The Review of Economics and Statistics, MIT Press, vol. 89(1), pages 88-99, February.
    57. Niels Skipper, 2010. "On Utilization and Stockpiling of Prescription Drugs when Co-payments Increase: Heterogeneity across Types of Drugs," Economics Working Papers 2010-12, Department of Economics and Business Economics, Aarhus University.
    58. Alan T. Sorensen, 2000. "Equilibrium Price Dispersion in Retail Markets for Prescription Drugs," Journal of Political Economy, University of Chicago Press, vol. 108(4), pages 833-862, August.
    59. David Reiffen & Michael R. Ward, 2005. "Generic Drug Industry Dynamics," The Review of Economics and Statistics, MIT Press, vol. 87(1), pages 37-49, February.
    60. Zweifel, Peter & Crivelli, Luca, 1996. "Price Regulation of Drugs: Lessons from Germany," Journal of Regulatory Economics, Springer, vol. 10(3), pages 257-273, November.
    61. Nabin Munirul Haque & Mohan Vijay & Nicholas Aaron & Sgro Pasquale M., 2012. "Therapeutic Equivalence and the Generic Competition Paradox," The B.E. Journal of Economic Analysis & Policy, De Gruyter, vol. 12(1), pages 1-26, November.
    62. Iván Moreno-Torres & Jaume Puig-Junoy & Joan-Ramon Borrell, 2009. "Generic Entry into the Regulated Spanish Pharmaceutical Market," Review of Industrial Organization, Springer;The Industrial Organization Society, vol. 34(4), pages 373-388, June.
    Full references (including those not matched with items on IDEAS)

    Citations

    Citations are extracted by the CitEc Project, subscribe to its RSS feed for this item.
    as


    Cited by:

    1. Unsorg Maximiliane, 2022. "Reference pricing systems on the pharmaceutical market," German Economic Review, De Gruyter, vol. 23(3), pages 403-421, August.
    2. Suppliet, Moritz, 2020. "Umbrella branding in pharmaceutical markets," Journal of Health Economics, Elsevier, vol. 73(C).
    3. Mahlich Jörg & Sindern Jörn & Suppliet Moritz, 2015. "Vergleichbarkeit internationaler Arzneimittelpreise," Perspektiven der Wirtschaftspolitik, De Gruyter, vol. 16(2), pages 164-172, June.
    4. Tomaso Duso & Annika Herr & Moritz Suppliet, 2014. "The Welfare Impact Of Parallel Imports: A Structural Approach Applied To The German Market For Oral Anti‐Diabetics," Health Economics, John Wiley & Sons, Ltd., vol. 23(9), pages 1036-1057, September.
    5. Herr, Annika, 2012. "Rationalisierung und Wettbewerb im Arzneimittelmarkt," DICE Ordnungspolitische Perspektiven 31, Heinrich Heine University Düsseldorf, Düsseldorf Institute for Competition Economics (DICE).
    6. Herr, Annika & Stühmeier, Torben & Wenzel, Tobias, 2014. "Reference pricing and cost-sharing: Theory and evidence on German off-patent drugs," VfS Annual Conference 2014 (Hamburg): Evidence-based Economic Policy 100556, Verein für Socialpolitik / German Economic Association.

    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. Kaiser, Ulrich & Mendez, Susan J. & Rønde, Thomas & Ullrich, Hannes, 2014. "Regulation of pharmaceutical prices: Evidence from a reference price reform in Denmark," Journal of Health Economics, Elsevier, vol. 36(C), pages 174-187.
    2. Brekke, Kurt R. & Canta, Chiara & Straume, Odd Rune, 2016. "Reference pricing with endogenous generic entry," Journal of Health Economics, Elsevier, vol. 50(C), pages 312-329.
    3. Suppliet, Moritz, 2020. "Umbrella branding in pharmaceutical markets," Journal of Health Economics, Elsevier, vol. 73(C).
    4. Susan J. Méndez, 2018. "Parallel trade of pharmaceuticals: The Danish market for statins," Health Economics, John Wiley & Sons, Ltd., vol. 27(2), pages 333-356, February.
    5. repec:nip:nipewp:06/2015 is not listed on IDEAS
    6. Matteo Galizzi & Simone Ghislandi & Marisa Miraldo, 2011. "Effects of Reference Pricing in Pharmaceutical Markets," PharmacoEconomics, Springer, vol. 29(1), pages 17-33, January.
    7. Kurt R. Brekke & Chiara Canta & Odd Rune StraumeAuthor-Email: o.r.straume@eeg.uminho.p, 2015. "Does Reference Pricing Drive Out Generic Competition in Pharmaceutical Markets? Evidence from a Policy Reform," NIPE Working Papers 6/2015, NIPE - Universidade do Minho.
    8. Granlund, David & Bergman, Mats A., 2018. "Price competition in pharmaceuticals – Evidence from 1303 Swedish markets," Journal of Health Economics, Elsevier, vol. 61(C), pages 1-12.
    9. Brekke, Kurt R. & Konigbauer, Ingrid & Straume, Odd Rune, 2007. "Reference pricing of pharmaceuticals," Journal of Health Economics, Elsevier, vol. 26(3), pages 613-642, May.
    10. Brekke, Kurt R. & Holmas, Tor Helge & Straume, Odd Rune, 2011. "Reference pricing, competition, and pharmaceutical expenditures: Theory and evidence from a natural experiment," Journal of Public Economics, Elsevier, vol. 95(7), pages 624-638.
    11. Mats A. Bergman & David Granlund & Niklas Rudholm, 2017. "Squeezing the Last Drop Out of Your Suppliers: An Empirical Study of Market-Based Purchasing Policies for Generic Pharmaceuticals," Oxford Bulletin of Economics and Statistics, Department of Economics, University of Oxford, vol. 79(6), pages 969-996, December.
    12. David Granlund & Miyase Koksal-Ayhan, 2015. "Parallel imports and a mandatory substitution reform: a kick or a muff for price competition in pharmaceuticals?," The European Journal of Health Economics, Springer;Deutsche Gesellschaft für Gesundheitsökonomie (DGGÖ), vol. 16(9), pages 969-983, December.
    13. Herr, Annika & Stühmeier, Torben & Wenzel, Tobias, 2014. "Reference pricing and cost-sharing: Theory and evidence on German off-patent drugs," VfS Annual Conference 2014 (Hamburg): Evidence-based Economic Policy 100556, Verein für Socialpolitik / German Economic Association.
    14. Bergman , Mats A. & Granlund, David & Rudholm, Niklas, 2016. "Squeezing the last drop out of your suppliers: an empirical study of market-based purchasing policies for generic pharmaceuticals," Umeå Economic Studies 921, Umeå University, Department of Economics.
    15. Ivan Moreno-Torres, 2011. "Generic drugs in Spain: price competition vs. moral hazard," Working Papers XREAP2011-04, Xarxa de Referència en Economia Aplicada (XREAP), revised May 2011.
    16. Königbauer, Ingrid, 2006. "Dealing with Rising Health Care Costs: The Case of Pharmaceuticals," Munich Dissertations in Economics 5640, University of Munich, Department of Economics.
    17. Hokkanen, Joni & Kangasharju, Aki & Linnosmaa, Ismo & Valtonen, Hannu, 2012. "Generic substitution policy, prices and market structure: evidence from a quasi-experiment in Finland," Working Papers 35, VATT Institute for Economic Research.
    18. Granlund, David & Yesim Köksal, Miyase, 2011. "Parallel Imports and Mandatory Substitution Reform: A kick or a muff for price competition in pharmaceuticals," Working Papers in Economics 496, University of Gothenburg, Department of Economics.
    19. F. Antoñanzas & C. A. Juárez-Castelló & R. Rodríguez-Ibeas, 2017. "Endogenous versus exogenous generic reference pricing for pharmaceuticals," International Journal of Health Economics and Management, Springer, vol. 17(4), pages 413-432, December.
    20. Bergman, Mats & Granlund, David & Rudholm, Niklas, 2016. "Squeezing the last drop out of your suppliers: an empirical study of market-based purchasing policies for generic pharmaceuticals," HUI Working Papers 116, HUI Research.
    21. Patricia M. Danzon & Eric L. Keuffel, 2014. "Regulation of the Pharmaceutical-Biotechnology Industry," NBER Chapters, in: Economic Regulation and Its Reform: What Have We Learned?, pages 407-484, National Bureau of Economic Research, Inc.

    More about this item

    Keywords

    pharmaceutical prices; cost-sharing; co-payments; reference pricing; regulation; firm behavior; health insurance;
    All these keywords.

    JEL classification:

    • I1 - Health, Education, and Welfare - - Health
    • L11 - Industrial Organization - - Market Structure, Firm Strategy, and Market Performance - - - Production, Pricing, and Market Structure; Size Distribution of Firms

    NEP fields

    This paper has been announced in the following NEP Reports:

    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:tiu:tiucen:4d692f0e-8577-4392-b413-269be650c250. 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: . General contact details of provider: http://center.uvt.nl .

    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: Richard Broekman (email available below). General contact details of provider: http://center.uvt.nl .

    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.