Drivers of Medical Travel at the National Level

  • Klaus Schmerler
Part of the Developments in Health Economics and Public Policy book series (HEPP, volume 13)


Chapter 4 contains the first empirical investigation of drivers of medical travel at the national level. The author proposes a gravity model, provides an introduction to its theoretical underpinnings and discusses its assumptions and applicability to medical travel. A dynamic extension of the gravity model allows the investigation of candidate drivers including cultural proximity, networks and word-of-mouth. Various specifications test the robustness of the results.


  1. Afman, E. R., & Maurel, M. (2010). Diplomatic relations and trade reorientation in transition countries. In P. A. G. Van Bergeijk & S. Brakman (Eds.), The gravity model in international trade: Advances and applications (pp. 278–295). Cambridge: Cambridge University Press.CrossRefGoogle Scholar
  2. Allison, P. D., & Waterman, R. P. (2002). Fixed-effects negative binomial regression models. Sociological Methodology, 32, 247–265.CrossRefGoogle Scholar
  3. Anderson, J. E. (1979). A theoretical foundation for the gravity equation. The American Economic Review, 69, 106–116.Google Scholar
  4. Anderson, J. E. (2011). The gravity model. Annual Review of Economics, 3, 133–160. Scholar
  5. Anderson, J. E., & van Wincoop, E. (2003). Gravity with gravitas: A solution to the border puzzle. The American Economic Review, 93, 170–190.CrossRefGoogle Scholar
  6. Anderson, J. E., & van Wincoop, E. (2004). Trade costs. Journal of Economic Literature, 42, 691–751.CrossRefGoogle Scholar
  7. Anderson, J. E., & Yotov, Y. V. (2010). The changing incidence of geography. American Economic Review, 100, 2157–2186.CrossRefGoogle Scholar
  8. Anderson, S. P., de Palma, A., & Thisse, J.-F. (1992). Discrete choice theory of product differentiation. Cambridge: MIT Press.Google Scholar
  9. Arkolakis, C., Costinot, A., & Rodríguez-Clare, A. (2012). New trade models, same old gains? American Economic Review, 102, 94–130. Scholar
  10. Baldwin, R., & Taglioni, D. (2007). Trade effects of the euro: A comparison of estimators. Journal of Economic Integration, 22, 780–818.CrossRefGoogle Scholar
  11. Balistreri, E. J., & Hillberry, R. H. (2006). Trade frictions and welfare in the gravity model: How much of the iceberg melts? The Canadian Journal of Economics, 38, 247–265.CrossRefGoogle Scholar
  12. Baltagi, B. H. (2013). Econometric analysis of panel data (5th ed.). Chichester: Wiley.Google Scholar
  13. Belenkiy, M. (2008). Robustness of the extensive margin in the Helpman, Melitz and Rubinstein (HMR) model (MPRAPaper 17913). Munich: University Library of Munich.Google Scholar
  14. Berger, H., & Nitsch, V. (2008). Zooming out: The trade effect of the euro in historical perspective. Journal of International Money and Finance, 27, 1244–1260. Scholar
  15. Bergstrand, J. H. (1985). The gravity equation in international trade: Some microeconomic foundations and empirical evidence. The Review of Economics and Statistics, 67, 474–481.CrossRefGoogle Scholar
  16. Bergstrand, J. H. (1989). The generalized gravity equation, monopolistic competition, and the factor-proportions theory in international trade. The Review of Economics and Statistics, 71, 143–153.CrossRefGoogle Scholar
  17. Bergstrand, J. H. (1990). The heckscher-ohlin-samuelson model, the linder hypothesis and the determinants of bilateral intra-industry trade. The Economic Journal, 100, 1216–1229.CrossRefGoogle Scholar
  18. Berry, S. (1994). Estimating discrete-choice models of product differentiation. The Rand Journal of Economics, 25, 242–262.CrossRefGoogle Scholar
  19. Berry, S., Levinsohn, J., & Pakes, A. (1995). Automobile prices in market equilibrium. Econometrica, 63, 841–890.CrossRefGoogle Scholar
  20. Bookman, M. Z., & Bookman, K. R. (2007). Medical tourism in developing countries. New York: Palgrave Macmillan.CrossRefGoogle Scholar
  21. Bosker, E. M., & Garretsen, H. (2010). Trade costs, market access, and economic geography: Why the empirical specification of trade costs matters. In P. A. G. Van Bergeijk & S. Brakman (Eds.), The gravity model in international trade: Advances and applications (pp. 193–223). Cambridge: Cambridge University Press.CrossRefGoogle Scholar
  22. Bosquet, C., & Boulhol, H. (2014). Applying the GLM variance assumption to overcome the scale-dependence of the negative binomial QGPML estimator. Econometric Reviews, 33, 772–784. Scholar
  23. Bun, M. J. G., & Klaassen, F. J. G. M. (2002). The importance of dynamics in panel gravity models of trade. SSRN Journal.
  24. Cameron, A. C., & Trivedi, P. K. (2009). Microeconometrics: Methods and applications, 8. Printing. Cambridge: Cambridge University Press.Google Scholar
  25. Campbell, D. L. (2013). Estimating the impact of currency unions on trade: Solving the glick and rose puzzle. The World Economy, 36, 1278–1293. Scholar
  26. Chaney, T. (2008). Distorted gravity: The intensive and extensive margins of international trade. American Economic Review, 98, 1707–1721. Scholar
  27. Cheng, I.-H., & Wall, H. J. (2005). Controlling for heterogeneity in gravity models of trade and integration. Federal Reserve Bank of St. Louis Review, 87, 49–63.Google Scholar
  28. Crone, R. K. (2008). Flat medicine? Exploring trends in the globalization of health care. Academic Medicine, 83, 117–121. Scholar
  29. Dalgin, M., Mitra, D., & Trindade, V. (2004). Inequality, nonhomothetic preferences, and trade: A gravity approach (NBER Working Paper Series 10800). National Bureau of Economic Research.Google Scholar
  30. Deardorff, A. (1998). Determinants of bilateral trade: Does gravity work in a neoclassical world? In J. A. Frankel (Ed.), The regionalization of the world economy (Vol. 1, pp. 7–32). Chicago: University of Chicago Press.Google Scholar
  31. Deb, P., & Trivedi, P. K. (2013). Finite mixture for panels with fixed effects. Journal of Econometric Methods, 2, 35–51. Scholar
  32. DESTATIS. (2012). Bevölkerung und Erwerbstätigkeit: Wanderungen. Fachserie 1 Reihe 1.2, Wiesbaden.Google Scholar
  33. Disdier, A.-C., & Head, K. (2008). The puzzling persistence of the distance effect on bilateral trade. The Review of Economics and Statistics, 90, 37–48.CrossRefGoogle Scholar
  34. Dixit, A. K., & Stiglitz, J. E. (1977). Monopolistic competition and optimum product diversity. The American Economic Review, 67, 297–308.Google Scholar
  35. Duanmu, J.-L., & Guney, Y. (2013). Heterogeneous effect of ethnic networks on international trade of Thailand: The role of family ties and ethnic diversity. International Business Review, 22, 126–139. Scholar
  36. Dunlevy, J. A. (2006). The influence of corruption and language on the protrade effect of immigrants: Evidence from the American states. The Review of Economics and Statistics, 88, 182–186.CrossRefGoogle Scholar
  37. Eichengreen, B., & Irwin, D. A. (1998). The role of history in bilateral trade flows. In J. A. Frankel (Ed.), The regionalization of the world economy (pp. 33–62). Chicago: University of Chicago Press.Google Scholar
  38. Engel, C. (2002). Comment on borders, trade, and welfare. In S. M. Collins & D. Rodrik (Eds.), Brookings trade forum: 2001. Washington, DC: Brookings Institution Press.Google Scholar
  39. Esiyok, B., Çakar, M., & Kurtulmuşoğlu, F. B. (2017). The effect of cultural distance on medical tourism. Journal of Destination Marketing & Management, 6, 66–75. Scholar
  40. Felbermayr, G. J., & Toubal, F. (2010). Cultural proximity and trade. European Economic Review, 54, 279–293. Scholar
  41. Fernández, C., Ley, E., & Steel, M. F. J. (2001). Model uncertainty in cross-country growth regressions. Journal of Applied Econometrics, 16, 563–576. Scholar
  42. Fidrmuc, J. (2009). Gravity models in integrated panels. Empirical Economics, 37, 435–446. Scholar
  43. Fitzgerald, D. (2012). Trade costs, asset market frictions, and risk sharing. American Economic Review, 102, 2700–2733. Scholar
  44. Gohin, A., & Féménia, F. (2009). Estimating price elasticities of food trade functions: How relevant is the CES-based gravity approach? Journal of Agricultural Economics, 60, 253–272. Scholar
  45. Gould, D. M. (1994). Immigrant links to the home country: Empirical implications for U.S. bilateral trade flows. The Review of Economics and Statistics, 76, 302–316.CrossRefGoogle Scholar
  46. Greene, W. (2005). Functional form and heterogeneity in models for count data. Foundations and Trends® in Econometrics, 1, 113–218. Scholar
  47. Griffith, D. A. (2000). A linear regression solution to the spatial autocorrelation problem. Journal of Geographical Systems, 2, 141–156.CrossRefGoogle Scholar
  48. Griffith, D. A. (2002). A spatial filtering specification for the auto-Poisson model. Statistics and Probability Letters, 58, 245–251.CrossRefGoogle Scholar
  49. Guo, M. (2015). Estimating international consumption risk sharing and financial frictions with gravity equation. Beijing: Department of Economics, School of Economics and Management, Tsinghua University.Google Scholar
  50. Hanefeld, J., Lunt, N., Smith, R., & Horsfall, D. (2015). Why do medical tourists travel to where they do? The role of networks in determining medical travel. Social Science & Medicine, 124, 356–363. Scholar
  51. Hausman, J. A., & Taylor, W. E. (1981). Panel data and unobservable individual effects. Econometrica, 49, 1377–1398.CrossRefGoogle Scholar
  52. Hausman, J. A., Hall, B. H., & Grilliches, Z. (1984). Econometric models for count data with an application to the Patents-R & D relationship. Econometrica, 52, 909–938.CrossRefGoogle Scholar
  53. Head, K., & Mayer, T. (2010). Illusory border effects: Distance mismeasurement inflates estimates of home bias in trade. In P. A. G. Van Bergeijk & S. Brakman (Eds.), The gravity model in international trade: Advances and applications (pp. 165–192). Cambridge: Cambridge University Press.CrossRefGoogle Scholar
  54. Head, K., & Mayer, T. (2013). Gravity equations: Workhorse, toolkit and cookbook (CEPII Working Paper 27). Paris: CEPII.Google Scholar
  55. Head, K., & Ries, J. (1998). Immigration and trade creation: Econometric evidence from Canada. The Canadian Journal of Economics, 31, 47–62.CrossRefGoogle Scholar
  56. Helpman, E., Melitz, M., & Rubinstein, Y. (2008). Estimating trade flows: Trading partners and trading volumes. Quarterly Journal of Economics, 123, 441–487. Scholar
  57. Heung, V. C. S., Kucukusta, D., & Song, H. (2010). A conceptual model of medical tourism: Implications for future research. Journal of Travel and Tourism Marketing, 27, 236–251.CrossRefGoogle Scholar
  58. Hofstede, G. H. (1980). Culture’s consequences: International differences in work-related values, Cross-cultural research and methodology series (p. 5). Newbury Park: Sage.Google Scholar
  59. Holmberg, H., & Lundevaller, E. H. (2015). A test for robust detection of residual spatial autocorrelation with application to mortality rates in Sweden. Spatial Statistics, 14, 365–381. Scholar
  60. Johnson, T. J., & Garman, A. N. (2015). Demand for international medical travel to the USA. Tourism Economics, 21, 1061–1077. Scholar
  61. Johnston, R., Crooks, V. A., & Snyder, J. (2012). “I didn’t even know what I was looking for”: A qualitative study of the decision-making processes of Canadian medical tourists. Globalization and Health, 8, 23. Scholar
  62. Jotikasthira, N. (2010). Salient factors influencing medical tourism destination choice. Dissertation: Southern Cross University.Google Scholar
  63. Keckley, P. H., & Eselius, L. L. (2009). 2009 survey of health care consumers: Key findings, strategic implications. Washington, DC: Deloitte Center for Health Solutions.Google Scholar
  64. Klijs, J., Ormond, M., Mainil, T., Peerlings, J., & Heijman, W. (2016). A state-level analysis of the economic impacts of medical tourism in Malaysia. Asian-Pacific Economic Literature, 30, 3–29. Scholar
  65. Klingenberger, D. (2009). Dentaltourismus und Auslandszahnersatz: Empirische Zahlungsbereitschaftsanalysen auf der Grundlage repräsentativer Stichproben im Jahre 2008. In Materialienreihe/Institut der Deutschen Zahnärzte (Vol. 32). Köln: Dt. Zahnärzte-Verlag.Google Scholar
  66. Krautheim, S. (2007). Gravity and information: Heterogeneous firms, exporter networks and the ‘Distance Puzzle’ (EUI Working Paper ECO 2007/51). European University Institute.Google Scholar
  67. Leamer, E. E., & Stern, R. M. (1970). Quantitative international economics. Chicago: Aldine Publishing Company.Google Scholar
  68. Linnemann, H. (1966). An econometric study of international trade flows. Amsterdam: North-Holland Pub..Google Scholar
  69. Lunt, N., Jin, K. N., Horsfall, D., & Hanefeld, J. (2014). Insights on medical tourism: Markets as networks and the role of strong ties. Korean Social Science Journal, 41, 19–37. Scholar
  70. McCallum, J. (1995). National borders matter. The American Economic Review, 85, 615–623.Google Scholar
  71. Melitz, M. J. (2003). The impact of trade on intra-industry reallocations and aggregate industry productivity. Econometrica, 71, 1695–1725.CrossRefGoogle Scholar
  72. Melitz, J., & Toubal, F. (2014). Native language, spoken language, translation and trade. Journal of International Economics, 93, 351–363.CrossRefGoogle Scholar
  73. Möhlmann, J. L., Ederveen, S., de Groot, H. L. F., & Linders, G.-J. M. (2010). Intangible barriers to international trade: A sectorial approach. In P. A. G. Van Bergeijk & S. Brakman (Eds.), The gravity model in international trade: Advances and applications (pp. 224–251). Cambridge: Cambridge University Press.CrossRefGoogle Scholar
  74. Mundlak, Y. (1978). On the pooling of time series and cross section data. Econometrica, 46, 69–85.CrossRefGoogle Scholar
  75. Musa, G., Thirumoorthi, T., & Doshi, D. (2012). Travel behaviour among inbound medical tourists in Kuala Lumpur. Current Issues in Tourism, 15, 525–543. Scholar
  76. Naranong, A., & Naranong, V. (2011). The effects of medical tourism: Thailand’s experience. Bulletin of the World Health Organization, 89, 336–344. Scholar
  77. Nickell, S. (1981). Biases in dynamic models with fixed effects. Econometrica, 49, 1417–1426.CrossRefGoogle Scholar
  78. Noree, T., Hanefeld, J., & Smith, R. (2016). Medical tourism in Thailand: A cross-sectional study. Bulletin of the World Health Organization, 94, 30–36. Scholar
  79. Novy, D. (2013). International trade without CES: Estimating translog gravity. Journal of International Economics, 89, 271–282. Scholar
  80. Petrin, A. (2002). Quantifying the benefits of new products: The case of the minivan. Journal of Political Economy, 110, 705–729.CrossRefGoogle Scholar
  81. Pöyhönen, P. (1963). A tentative model for the volume of trade between countries. Weltwirtschaftliches Archiv, 90, 93–100.Google Scholar
  82. Rabe-Hesketh, S., & Skrondal, A. (2012). Multilevel and longitudinal modeling using stata (3rd ed.). College Station Tex: Stata Press publication.Google Scholar
  83. Rabe-Hesketh, S., & Skrondal, A. (2013). Avoiding biased versions of Wooldridge’s simple solution to the initial conditions problem. Economics Letters, 120, 346–349. Scholar
  84. Rauch, J. E. (1999). Networks versus markets in international trade. Journal of International Economics, 48, 7–35.CrossRefGoogle Scholar
  85. Rauch, J. E. (2001). Business and social networks in international trade. Journal of Economic Literature, 39, 1177–1203.CrossRefGoogle Scholar
  86. Rose, A. K. (2001). Currency unions and trade: The effect is large. Economic Policy, 16, 449–461. Scholar
  87. Rose, A. K., Lockwood, B., & Quah, B. (2000). One money, one market: The effect of common currencies on trade. Economic Policy, 15, 7–45.CrossRefGoogle Scholar
  88. Santos Silva, J. M. C., & Tenreyro, S. (2006). The log of gravity. The Review of Economics and Statistics, 88, 641–658.CrossRefGoogle Scholar
  89. Santos Silva, J. M. C., & Tenreyro, S. (2011). Further simulation evidence on the performance of the Poisson pseudo-maximum likelihood estimator. Economics Letters, 112, 220–222. Scholar
  90. Santos Silva, J. M. C., & Tenreyro, S. (2015). Trading partners and trading volumes: Implementing the Helpman-Melitz-Rubinstein model empirically. Oxford Bulletin of Economics and Statistics, 77, 93–105. Scholar
  91. Savage, I. R., Deutsch, K. W., & Girshick, M. (1960). A statistical model of the gross analysis of transaction flows. Econometrica, 28, 551–572.CrossRefGoogle Scholar
  92. Sheu, G. (2014). Price, quality, and variety: Measuring the gains from trade in differentiated products. American Economic Journal: Applied Economics, 6, 66–89. Scholar
  93. Skrondal, A., & Rabe-Hesketh, S. (2014). Handling initial conditions and endogenous covariates in dynamic/transition models for binary data with unobserved heterogeneity. Journal of the Royal Statistical Society: Series C, 63, 211–237. Scholar
  94. Straathof, B. (2008). Gravity with gravitas: Comment (CPB Discussion Paper 111). The Hague: CPB Netherlands Bureau for Economic Policy Analysis.Google Scholar
  95. Tinbergen, J. (1962). Shaping the world economy: Suggestions for an international economic policy. New York: Twentieth Century Fund.Google Scholar
  96. Van Bergeijk, P. A. G., & Brakman, S. (2010). Introduction: The comeback of the gravity model. In P. A. G. Van Bergeijk & S. Brakman (Eds.), The gravity model in international trade: Advances and applications (pp. 1–26). Cambridge: Cambridge University Press.CrossRefGoogle Scholar
  97. Veerasoontorn, R., & Beise-Zee, R. (2010). International hospital outshopping: A staged model of push and pull factors. International Journal of Pharmaceutical and Healthcare Marketing, 4, 247–264. Scholar
  98. Wall, H. J. (1999). Using the gravity model to estimate the costs of protection. Federal Reserve Bank of St. Louis Review, 81, 33–40.Google Scholar
  99. Wang, Y., Kockelman, K. M., & Wang, X. (2013). Understanding spatial filtering for analysis of land use-transport data. Journal of Transport Geography, 31, 123–131. Scholar
  100. Wongkit, M., & McKercher, B. (2013). Toward a typology of medical tourists: A case study of Thailand. Tourism Management, 38, 4–12. Scholar
  101. Wooldridge, J. M. (2005). Simple solutions to the initial conditions problem in dynamic, nonlinear panel data models with unobserved heterogeneity. Journal of Applied Econometrics, 20, 39–54. Scholar
  102. Yeoh, E., Othman, K., & Ahmad, H. (2013). Understanding medical tourists: Word-of-mouth and viral marketing as potent marketing tools. Tourism Management, 34, 196–201. Scholar

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© Springer Nature Switzerland AG 2018

Authors and Affiliations

  • Klaus Schmerler
    • 1
  1. 1.Martin Luther University Halle-WittenbergHalle (Saale)Germany

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