Testing Distributional Dependence in the Becker-DeGroot-Marschak ...

4.5 Results of Testable Predictions
As seen in Section 4.1, only three subjects submitted bids consistent with them being rational
expected-utility maximizers who have certain and unchanging valuations: that is, both their first
and last bids were identical across all 20 rounds of the BDM phase (within subject). 35 Six more
subjects had some variation in their first bids but no variation in their last bids for each round,
consistent with the standard model with learning. 36 Collectively, the behavior of these nine
subjects is also consistent with any of the models presented, provided that the magnitude of the
purported individual biases is small in relation to the discreteness of the distributions used. Put
another way, to a greater or lesser degree 60 of the 69 subjects submitted bids that did not
conform with the predictions of the standard model.
Looking at the across-subjects data, there is no support for the prediction made by the model
of Horowitz that elicitations would flee mass. As seen in Table 6, Table 7, and Table 8—which
look only at last elicitations to help control for possible effects of learning—the distribution with
more mass to the left never yields a higher average WTP that is in any way remotely
significant. 37
The within-subjects data show relatively few of subjects exhibit mass-fleeing bias. Of the
seven with correlations of less than -0.5 in Figure 5, not one of them clearly represents the case
predicted by Horowitz and Kőszegi-Rabin, where a subject with a relatively high valuation would
increase her reported WTP as a result of asymmetric regret or the attachment effect. 38 In
contrast, one of the subjects specifically describes being motivated by the comparison effect: “I
did not want to pay more than 5. If it was very likely to be less than five my willingness to pay
35 Again, see the charts for subjects 41, 52, and 56 in Appendix B.
36 See the charts for subjects 13, 18, 29, 44, 50, 64 in Appendix B.
37 The closest case would be where distribution #7 is compared to distribution #11 in Panel A of Table 8.
38 Of the seven, six report average WTPs that are lower than the mean or median of all of the distributions used.
Subject 68 had the highest average WTP at 3.225, but as seen in Appendix B this subject is giving purely bimodal
responses that reflect the support of the distribution; there is no mass-fleeing response within the set of distributions
with low support.
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