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Subjective Bayesian beliefs

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Abstract

A large literature suggests that many individuals do not apply Bayes’ Rule when making decisions that depend on them correctly pooling prior information and sample data. We replicate and extend a classic experimental study of Bayesian updating from psychology, employing the methods of experimental economics, with careful controls for the confounding effects of risk aversion. Our results show that risk aversion significantly alters inferences on deviations from Bayes’ Rule.

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Notes

  1. The most unlikely pattern is (5,0) with probability of occurring equal to 0.044, followed by the pattern (7,2) with probability 0.091, and the pattern (11,6) with probability 0.104. Based on these probabilities we chose the frequency of each sample size to roughly equalize the expected frequency of the most unlikely patterns in each session.

  2. For example, each subject filled out 30 betting sheets, such as the one shown by Table 1. At the end of the experiment we first randomly chose, for each subject, one of these betting sheets, and then we chose 1 of the 19 bookies within that selected sheet. If the subject placed the allocated £3 on the box that was actually chosen, he was paid the amount that corresponds to the odds offered by that bookie.

  3. We provide a complete derivation of the application of Bayes’ Rule for this process in Appendix 2, which can be found in the accompanying online document.

  4. In our lottery experiments the subjects are told at the outset that any expression of indifference would mean that the experimenter would toss a fair coin to make the decision for them if that choice was selected to be played out. Hence one can modify the likelihood to take these responses into account either by recognizing this is a third option, the compound lottery of the two lotteries, or alternatively that such choices imply a 50:50 mixture of the likelihood of choosing either lottery, as illustrated by Harrison and Rutström (2008; p.71). We do not consider indifference here because it was an extremely rare event.

  5. The normalizing term ν is defined as the maximum utility over all prizes in this lottery pair minus the minimum utility over all prizes in this lottery pair, and ensures that the normalized EU difference [(EUR - EUL)/ν] remains in the unit interval. As μ → ∞ this specification collapses ∇EU to 0 for any values of EUR and EUL, so the probability of either choice converges to ½. So a larger μ means that the difference in the EU of the two lotteries, conditional on the estimate of r, has less predictive effect on choices. Thus μ can be viewed as a parameter that flattens out, or “sharpens,” the link functions implicit in (4). This is just one of several different types of error story that could be used, and Wilcox (2008) provides a masterful review of the implications of the strengths and weaknesses of the major alternatives.

  6. The normalizing term ν is given by the value of r and the lottery parameters, which are part of X.

  7. This qualitative result is exactly the same as one finds using a Quadratic or Linear scoring rule (providing, in the latter case, that one does not go to the extreme of exact risk neutrality): see Andersen et al. (2014).

  8. Holt and Smith (2009; §5) make exactly the same observation in a comparable study that we discuss further in Section 5.

  9. In its traditional form the RDU model assumes reduction of compound lotteries, a point we return to below. Our application here is unconventional in the application of concepts of “probabilistic sophistication” to a particular non-EUT model, in the spirit of Machina and Schmeidler (1992, 1995) and Grant (1995). It is unconventional in the sense of assuming that individuals behave as if they distort (weight) objective probabilities, but they are otherwise probabilistically sophisticated.

  10. In many physical processes, for example, threshold effects can lead to extreme outcomes rather than intermediate ones. So one person might believe the threshold has been exceeded, and another person might believe it has not.

References

  • Andersen, S., Fountain, J., Harrison, G. W., & Rutström, E. E. (2014). Estimating subjective probabilities. Journal of Risk & Uncertainty, 48, 207–229.

    Article  Google Scholar 

  • Andersen, S., Harrison, G. W., Lau, M. I., & Rutström, E. E. (2007). Valuation using multiple price list formats. Applied Economics, 39, 675–682.

    Article  Google Scholar 

  • Becker, G. M., DeGroot, M. H., & Marschak, J. (1964). Measuring utility by a single-response sequential method. Behavioral Science, 9, 226–232.

    Article  Google Scholar 

  • Davis, D. B., & Paté-Cornell, M. E. (1994). A challenge to the compound lottery axiom: a two-stage normative structure and comparison to other theories. Theory and Decision, 37, 267–309.

    Article  Google Scholar 

  • Eeckhoudt, L., Gollier, C., & Schlesinger, H. (1996). Changes in background risk and risk taking behavior. Econometrica, 64, 683–689.

    Article  Google Scholar 

  • Ellsberg, D. (1961). Risk, ambiguity, and the Savage axioms. Quarterly Journal of Economics, 75, 643–669.

    Article  Google Scholar 

  • Ergin, H., & Gul, F. (2009). A theory of subjective compound lotteries. Journal of Economic Theory, 144(3), 899–929.

    Article  Google Scholar 

  • Fiore, S. M., Harrison, G. W., Hughes, C. E., & Rutström, E. E. (2009). Virtual experiments and environmental policy. Journal of Environmental Economics and Management, 57, 65–86.

    Article  Google Scholar 

  • Ghirardato, P., Maccheroni, F., & Marinacci, M. (2004). Differentiating ambiguity and ambiguity attitude. Journal of Economic Theory, 118, 133–173.

    Article  Google Scholar 

  • Gilboa, I., Postlewaite, A. W., & Schmeidler, D. (2008). Probability and uncertainty in economic modeling. Journal of Economic Perspectives, 22, 173–188.

    Article  Google Scholar 

  • Gilboa, I., & Schmeidler, D. (1989). Maxmin expected utility with a non-unique prior. Journal of Mathematical Economics, 18, 141–153.

    Article  Google Scholar 

  • Gollier, C., & Pratt, J. W. (1996). Risk vulnerability and the tempering effect of background risk. Econometrica, 64, 1109–1123.

    Article  Google Scholar 

  • Gonzalez, R., & Wu, G. (1999). On the shape of the probability weighting function. Cognitive Psychology, 38, 129–166.

    Article  Google Scholar 

  • Grant, S. (1995). Subjective probability without monotonicity: or how Machina’s mom may also be probabilistically sophisticated. Econometrica, 63, 159–189.

    Article  Google Scholar 

  • Grether, D. M. (1992). Testing Bayes’ rule and the representativeness heuristic: some experimental evidence. Journal of Economic Behavior and Organization, 17, 31–57.

    Article  Google Scholar 

  • Griffin, D., & Tversky, A. (1992). The weighing of evidence and the determinants of confidence. Cognitive Psychology, 24, 411–435.

    Article  Google Scholar 

  • Gul, F. (1991). A theory of disappointment aversion. Econometrica, 59, 667–686.

    Article  Google Scholar 

  • Harrison, G. W. (1992). Theory and misbehavior of first-price auctions: reply. American Economic Review, 82, 1426–1443.

    Google Scholar 

  • Harrison, G. W., Johnson, E., McInnes, M. M., & Rutström, E. E. (2005). Risk aversion and incentive effects: comment. American Economic Review, 95, 897–901.

    Article  Google Scholar 

  • Harrison, G. W., Lau, M. I., & Williams, M. B. (2002). Estimating individual discount rates for Denmark: a field experiment. American Economic Review, 92, 1606–1617.

    Article  Google Scholar 

  • Harrison, G. W., & Rutström, E. E. (2008). Risk aversion in the laboratory. In J. C. Cox & G. W. Harrison (Eds.), Risk aversion in experiments (Vol. 12, pp. 41–197). Bingley: Emerald.

    Chapter  Google Scholar 

  • Hey, J. D., & Orme, C. (1994). Investigating generalizations of expected utility theory using experimental data. Econometrica, 62, 1291–1326.

    Article  Google Scholar 

  • Holt, C. A., & Laury, S. K. (2002). Risk aversion and incentive effects. American Economic Review, 92, 1644–1655.

    Article  Google Scholar 

  • Holt, C. A., & Smith, A. M. (2009). An update on Bayesian updating. Journal of Economic Behavior & Organization, 69, 125–134.

    Article  Google Scholar 

  • Klibanoff, P., Marinacci, M., & Mukerji, S. (2005). A smooth model of decision making under ambiguity. Econometrica, 73, 1849–1892.

    Article  Google Scholar 

  • Machina, M. J., & Schmeidler, D. (1992). A more robust definition of subjective probability. Econometrica, 60, 745–780.

    Article  Google Scholar 

  • Machina, M. J., & Schmeidler, D. (1995). Bayes without Bernoulli: simple conditions for probabilistically sophisticated choice. Journal of Economic Theory, 67, 106–128.

    Article  Google Scholar 

  • Nau, R. F. (2006). Uncertainty aversion with second-order utilities and probabilities. Management Science, 52, 136–156.

    Article  Google Scholar 

  • Neilson, W. S. (2010). A simplified axiomatic approach to ambiguity aversion. Journal of Risk and Uncertainty, 41, 113–124.

    Article  Google Scholar 

  • Plott, C. R., & Zeiler, K. (2005). The willingness to pay-willingness to accept gap, the ‘endowment effect,’ subject misconceptions, and experimental procedures for eliciting valuations. American Economic Review, 95, 530–545.

    Article  Google Scholar 

  • Prelec, D. (1998). The probability weighting function. Econometrica, 66, 497–527.

    Article  Google Scholar 

  • Quiggin, J. (1982). A theory of anticipated utility. Journal of Economic Behavior & Organization, 3, 323–343.

    Article  Google Scholar 

  • Quiggin, J. (2003). Background risk in generalized expected utility theory. Economic Theory, 22, 607–611.

    Article  Google Scholar 

  • Rieger, M. O., & Wang, M. (2006). Cumulative prospect theory and the St. Petersburg paradox. Economic Theory, 28, 665–679.

    Article  Google Scholar 

  • Rutström, E. E. (1998). Home-grown values and the design of incentive compatible auctions. International Journal of Game Theory, 27, 427–441.

    Article  Google Scholar 

  • Segal, U. (1987). The Ellsberg Paradox and risk aversion: an anticipated utility approach. International Economic Review, 28, 175–202.

    Article  Google Scholar 

  • Segal, U. (1988). Does the preference reversal phenomenon necessarily contradict the independence axiom? American Economic Review, 78, 233–236.

    Google Scholar 

  • Segal, U. (1990). Two-stage lotteries without the reduction axiom. Econometrica, 58, 349–377.

    Article  Google Scholar 

  • Segal, U. (1992). The independence axiom versus the reduction axiom: Must we have both? In W. Edwards (Ed.), Utility theories: Measurements and applications. Boston: Kluwer Academic Publishers.

    Google Scholar 

  • Savage, L. J. (1971). Elicitation of personal probabilities and expectations. Journal of American Statistical Association, 66, 783–801.

    Article  Google Scholar 

  • Savage, L. J. (1972). The foundations of statistics (2nd ed.). New York: Dover.

    Google Scholar 

  • Tversky, A., & Kahneman, D. (1992). Advances in prospect theory: cumulative representations of uncertainty. Journal of Risk & Uncertainty, 5, 297–323.

    Article  Google Scholar 

  • Wilcox, N. T. (2008). Predicting individual risky choices out-of-context: A critical stochastic modeling primer and Monte Carlo study. In J. Cox & G. W. Harrison (Eds.), Risk aversion in experiments (Vol. 12). Bingley: Emerald.

    Chapter  Google Scholar 

  • Wilcox, N. T. (2011). ‘Stochastically more risk averse:’a contextual theory of stochastic discrete choice under risk. Journal of Econometrics, 162, 89–104.

    Article  Google Scholar 

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Acknowledgments

Harrison thanks the U.S. National Science Foundation for research support under grants NSF/HSD 0527675 and NSF/SES 0616746, and we thank the referee and seminar and conference participants for valuable comments.

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Correspondence to Glenn W. Harrison.

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Antoniou, C., Harrison, G.W., Lau, M.I. et al. Subjective Bayesian beliefs. J Risk Uncertain 50, 35–54 (2015). https://doi.org/10.1007/s11166-015-9208-5

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