Journal of Risk and Uncertainty

, Volume 42, Issue 2, pp 145–159 | Cite as

Assessing small non-zero perceptions of chance: The case of H1N1 (swine) flu risks

  • Wändi Bruine de Bruin
  • Andrew M. Parker
  • Jürgen Maurer


Feelings of invulnerability, seen in judgments of 0% risk, can reflect misunderstandings of risk and risk behaviors, suggesting increased need for risk communication. However, judgments of 0% risk may be given by individuals who feel invulnerable, and by individuals who are rounding from small non-zero probabilities. We examined the effect of allowing participants to give more precise responses in the 0–1% range on the validity of reported probability judgments. Participants assessed probabilities for getting H1N1 influenza and dying from it conditional on infection, using a 0–100% visual linear scale. Those responding in the 0–1% range received a follow-up question with more options in that range. This two-step procedure reduced the use of 0% and increased the resolution of responses in the 0–1% range. Moreover, revised probability responses improved predictions of attitudes and self-reported behaviors. Hence, our two-step procedure allows for more precise and more valid measurement of perceived invulnerability.


Risk perceptions Expectations Visual linear scale Magnifier scale H1N1 flu 

JEL Classification

I10 D84 C83 



This work was supported by the National Institute of Aging [grant #R01AG20717] as well as the Center for the Advancement of Microbial Risk Assessment [EPA Star grant #R83236201], and benefited from support and comments by Courtney Gidengil, Tania Gutsche, Katherine Harris, Arie Kapteyn, Jeanne Ringel, Kip Viscusi, Bas Weerman, and an anonymous reviewer.


  1. Bruine de Bruin, W., & Carman, K.G. (in press). Measuring risk perceptions: What does the excessive use of 50% mean? Medical Decision Making. Google Scholar
  2. Bruine de Bruin, W., Fischhoff, B., Millstein, S. G., & Halpern-Felsher, B. L. (2000). Verbal and numerical expressions of probability: “it’s a fifty-fifty chance”. Organizational Behavior and Human Decision Processes, 81, 115–131.CrossRefGoogle Scholar
  3. Bruine de Bruin, W., Fischbeck, P. S., Stiber, N. A., & Fischhoff, B. (2002). What number is “fifty-fifty”? Redistributing excess 50% responses in risk perception studies. Risk Analysis, 22, 725–735.CrossRefGoogle Scholar
  4. Bruine de Bruin, W., Parker, A. M., & Fischhoff, B. (2007a). Individual differences in adult decision-making competence. Journal of Personality and Social Psychology, 92, 938–956.CrossRefGoogle Scholar
  5. Bruine de Bruin, W., Parker, A. M., & Fischhoff, B. (2007b). Can teens predict significant life events? Journal of Adolescent Health, 41, 208–210.CrossRefGoogle Scholar
  6. Bruine de Bruin, W., Downs, J. S., Murray, P. M., & Fischhoff, B. (2010). Can female adolescents tell whether they have a Chlamydia infection? Medical Decision Making, 30, 189–193.CrossRefGoogle Scholar
  7. Downs, J. S., Bruine de Bruin, W., Murray, P. J., & Fischhoff, B. (2004). When “it only takes once” fails: Perceived infertility predicts condom use and STI acquisition. Journal of Pediatric and Adolescent Gynecology, 17, 224.CrossRefGoogle Scholar
  8. Fischhoff, B., & Bruine de Bruin, W. (1999). Fifty-fifty=50%? Journal of Behavioral Decision Making, 12, 149–163.CrossRefGoogle Scholar
  9. Fischhoff, B., Welch, N., & Frederick, S. (1999). Construal processes in preference assessment. Journal of Risk and Uncertainty, 19, 139–164.CrossRefGoogle Scholar
  10. Fischhoff, B., Parker, A. M., Bruine de Bruin, W., Downs, J. S., Palmgren, C., Dawes, R., et al. (2000). Teen expectations for significant life events. Public Opinion Quarterly, 64, 189–205.CrossRefGoogle Scholar
  11. Gurmankin, A. D., Helweg-Larsen, M., Armstrong, K., Kimmel, S. E., & Volpp, K. G. M. (2005). Comparing the standard rating scale and the magnifier scale for assessing risk perceptions. Medical Decision Making, 25, 560–570.CrossRefGoogle Scholar
  12. Hurd, M. D., & McGarry, K. (1995). Evaluation of the subjective probabilities of survival in the Health and Retirement Study. Journal of Human Resources, 30, S268–S292.CrossRefGoogle Scholar
  13. Hurd, M. D., & McGarry, K. (2002). The predictive validity of subjective probabilities of survival. The Economic Journal, 112, 966–985.CrossRefGoogle Scholar
  14. Juster, T. (1996). Consumer Buying Intentions and Purchase Probability: an Experiment in Survey Design. Journal of the American Statistical Association, 61, 658–696.CrossRefGoogle Scholar
  15. Lillard, L. A., & Willis, R. (2001). Cognition and wealth: The importance of probabilistic thinking. Michigan Retirement Research Center Working Paper UM00-04.Google Scholar
  16. McClelland, G. H., Schulze, W. D., & Coursey, D. L. (1993). Insurance for low-probability hazards: a bimodal response to unlikely events. Journal of Risk and Uncertainty, 7, 96–116.CrossRefGoogle Scholar
  17. Millstein, S. G., & Halpern-Felsher, B. L. (2002). Judgments about risk and perceived invulnerability in adolescents and young adults. Journal of Research on Adolescence, 12, 399–422.CrossRefGoogle Scholar
  18. Parker, A. M., & Fischhoff, B. (2005). Decision-making competence: external validation through an individual-differences approach. Journal of Behavioral Decision Making, 18, 1–27.CrossRefGoogle Scholar
  19. Quadrel, M. J., Fischhoff, B., & Davis, W. (1993). Adolescent (in)vulnerability. American Psychologist, 48, 102–116.CrossRefGoogle Scholar
  20. Ritov, I., Baron, J., & Hershey, J. C. (1993). Framing effects in the evaluation of multiple risk reduction. Journal of Risk and Uncertainty, 6, 145–159.CrossRefGoogle Scholar
  21. Siegel, S., & Castellan, N. J., Jr. (1988). Nonparametric statistics for the behavioral sciences (2nd ed.). Boston: McGraw-Hill.Google Scholar
  22. Tversky, A., & Kahneman, D. (1981). The framing of decisions and the psychology of choice. Science, 211, 453–458.CrossRefGoogle Scholar
  23. Woloshin, S., Schwartz, L., Byram, S., Fischhoff, B., & Welch, H. G. (2000). A new scale for assessing perceptions of chance: a validation study. Medical Decision Making, 20, 298–307.CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media, LLC 2011

Authors and Affiliations

  • Wändi Bruine de Bruin
    • 1
  • Andrew M. Parker
    • 2
  • Jürgen Maurer
    • 3
  1. 1.Department of Social and Decision SciencesCarnegie Mellon UniversityPittsburghUSA
  2. 2.RAND CorporationPittsburghUSA
  3. 3.Faculté des Hautes Etudes Commerciales, Institut d’économie et management de la Sante (IEMS), Université de LausanneLausanneSwitzerland

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