Experimental Economics

, Volume 11, Issue 3, pp 299–314 | Cite as

Does context matter more for hypothetical than for actual contributions? Evidence from a natural field experiment

  • Francisco Alpizar
  • Fredrik CarlssonEmail author
  • Olof Johansson-Stenman


We investigated the importance of the social context for people’s voluntary contributions to a national park in Costa Rica, using a natural field experiment. Some subjects make actual contributions while others state their hypothetical contribution. Both the degree of anonymity and information provided about the contributions of others influence subject contributions in the hypothesized direction. We found a substantial hypothetical bias with regard to the amount contributed. However, the influence of the social contexts is about the same when the subjects make actual monetary contributions as when they state their hypothetical contributions. Our results have important implications for validity testing of stated preference methods: a comparison between hypothetical and actual behavior should be done for a given social context.


Environmental valuation Stated preference methods Voluntary contributions Anonymity Conformity Natural field experiment 


C93 Q50 


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  1. Akerlof, G., & Kranton, R. (2000). Economics and identity. Quarterly Journal of Economics, 115, 715–753. CrossRefGoogle Scholar
  2. Alpizar, A., Carlsson, F., & Johansson-Stenman, O. (2008, in press). Anonymity, reciprocity, and conformity: evidence from voluntary contributions to a National Park in Costa Rica. Journal of Public Economics. Google Scholar
  3. Bertrand, M., & Mullainathan, S. (2001). Do people mean what they say? Implications for subjective survey data. American Economic Review, Papers and Proceedings, 91, 67–72. Google Scholar
  4. Blamey, R. K., Bennett, J. W., & Morrison, M. D. (1999). Yea-saying in contingent valuation surveys. Land Economics, 75, 126–141. CrossRefGoogle Scholar
  5. Blumenschein, K., Blomquist, G. C., Johannesson, M., Horn, N., & Freeman, P. (2008). Eliciting willingness to pay without bias: evidence from a field experiment. Economic Journal, 118, 114–137. CrossRefGoogle Scholar
  6. Carson, R., Flores, N., Martin, K. M., & Wright, J. L. (1996). Contingent valuation and revealed preference methodologies: comparing the estimates for quasi-public goods. Land Economics, 72, 80–99. CrossRefGoogle Scholar
  7. Champ, P. A., Bishop, R. C., Brown, T. C., & McCollum, D. W. (1997). Using donation mechanisms to value nonuse benefits from public goods. Journal of Environmental Economics and Management, 33, 151–162. CrossRefGoogle Scholar
  8. Cookson, R. (2000). Framing effects in public goods experiments. Experimental Economics, 3, 55–79. Google Scholar
  9. Cummings, R. G., & Taylor, L. O. (1999). Unbiased value estimates for environmental goods: a cheap talk design for the contingent valuation method. American Economic Review, 89, 649–665. CrossRefGoogle Scholar
  10. Cummings, R., Elliot, S., Harrison, G., & Murphy, J. (1997). Are hypothetical referenda incentive compatible. Journal of Political Economy, 105, 609–621. CrossRefGoogle Scholar
  11. Fischbacher, U., Gaechter, S., & Fehr, E. (2001). Are people conditionally cooperative? Evidence from a public goods experiment. Economic Letters, 71, 397–404. CrossRefGoogle Scholar
  12. Frey, B., & Meier, S. (2004). Social Comparisons and pro-social behavior: testing “Conditional Cooperation” in a field experiment. American Economic Review, 94, 1717–1722. CrossRefGoogle Scholar
  13. Gächter, S. (2006). Conditional cooperation: behavioral regularities from the lab and the field and their policy implications. CeDEx Discussion Paper No. 2006-03, University of Nottingham. Google Scholar
  14. Hanemann, W. M. (1994). Valuing the environment through contingent valuation. Journal of Economic Perspectives, 8, 19–43. Google Scholar
  15. Harrison, G., & List, J. (2004). Field experiments. Journal of Economic Literature, 42, 1009–1055. CrossRefGoogle Scholar
  16. Heldt, T. (2005). Conditional cooperation in the field: cross-country skiers’ behavior in Sweden. Working Paper, Department of Economics and Society, Dalarna University. Google Scholar
  17. Hoffman, E., McCabe, K., Shachat, J., & Smith, V. (1994). Preferences, property rights, and anonymity in bargaining games. Games and Economic Behavior, 7, 346–380. CrossRefGoogle Scholar
  18. Holmes, T., & Kramer, R. (1995). An independent sample test of yea-saying and starting point bias in dichotomous-choice contingent valuation. Journal of Environmental Economics and Management, 29, 121–132. CrossRefGoogle Scholar
  19. Johansson-Stenman, O., & Svedsäter, H. (2007). Self image and the valuation of public goods. Working Paper, Department of Economics, Göteborg University. Google Scholar
  20. Kahneman, D., & Thaler, R. (2006). Anomalies: utility maximisation and experienced utility. Journal of Economic Perspectives, 20, 221–234. CrossRefGoogle Scholar
  21. Kahneman, D., Wakker, P., & Sarin, R. (1997). Back to Bentham? Explorations of experienced utility. Quarterly Journal of Economics, 112, 375–406. CrossRefGoogle Scholar
  22. Karlan, D., & List, J. (2007). What do laboratory experiments tell us about the real world? American Economic Review, 97, 1774–1793. CrossRefGoogle Scholar
  23. Landry, C., Lange, A., List, J., Price, M., & Rupp, N. (2006). Toward an understanding of the economics of charity: evidence from a field experiment. Quarterly Journal of Economics, 121, 747–782. CrossRefGoogle Scholar
  24. Legget, C., Kleckner, N., Boyle, K., Duffield, J., & Mitchell, R. (2003). Social desirability bias in contingent valuation surveys administered through in-person interviews. Land Economics, 79, 561–575. CrossRefGoogle Scholar
  25. Levitt, S., & List, J. (2008, in press). What do laboratory experiments tell us about the real world? Journal of Economic Perspectives. Google Scholar
  26. List, J. A., & Gallet, C. A. (2001). What experimental protocol influence disparities between actual and hypothetical values? Environmental and Resource Economics, 20, 241–254. CrossRefGoogle Scholar
  27. List, J. A., & Lucking-Reiley, D. (2002). The effects of seed money and refunds on charitable giving: experimental evidence from a university capital campaign. Journal of Political Economy, 110, 215–233. CrossRefGoogle Scholar
  28. List, J. A., Berrens, A. P., Bohara, A. K., & Kerkvliet, J. (2004). Examining the role of social isolation on stated preferences. American Economic Review, 94, 741–752. CrossRefGoogle Scholar
  29. Martin, R., & Randal, J. (2005). Voluntary contributions to a public good: a natural field experiment. Working Paper, Victoria University, New Zealand. Google Scholar
  30. McCabe, K., Smith, V., & LePore, M. (2000). Intentionality detection and “Mindreading”: why does game form matter? Proceedings of the National Academy of Sciences, 97, 4404–4409. CrossRefGoogle Scholar
  31. Mitchell, R., & Carson, R. (1989). Using surveys to value public goods: the contingent valuation method. Washington: Resources for the Future. Google Scholar
  32. Rousseeuw, P. J., & Leroy, A. M. (1987). Robust regression and outlier detection. New York: Wiley. CrossRefGoogle Scholar
  33. Russel, C., Bjorner, T., & Clark, C. (2003). Searching for evidence of alternative preferences, public as opposed to private. Journal of Economic Behavior and Organization, 51, 1–27. CrossRefGoogle Scholar
  34. Schkade, D. A., & Payne, J. W. (1994). How people respond to contingent valuation questions—a verbal protocol analysis of willingness-to-pay for an environmental regulation. Journal of Environmental Economics and Management, 26, 88–109. CrossRefGoogle Scholar
  35. Shang, J., & Croson, R. (2006). Field experiments in charitable contribution: the impact of social influence on the voluntary provision of public goods. Working Paper. Google Scholar
  36. Soetevent, A. R. (2005). Anonymity in giving in a natural context: an economic field experiment in thirty churches. Journal of Public Economics, 8, 2301–2323. CrossRefGoogle Scholar
  37. STATA (2005). STATA base reference manual. College Station: Stata Press. Google Scholar
  38. Tversky, A., & Kahneman, D. (1981). The framing of decisions and the psychology of choice. Science, 211, 453–458. CrossRefGoogle Scholar

Copyright information

© Economic Science Association 2008

Authors and Affiliations

  • Francisco Alpizar
    • 1
  • Fredrik Carlsson
    • 2
    Email author
  • Olof Johansson-Stenman
    • 2
  1. 1.Environment for Development CenterTropical Agricultural and Higher Education Center (CATIE)TurrialbaCosta Rica
  2. 2.Department of EconomicsGöteborg UniversityGöteborgSweden

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