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Travel behavior research shows that the disutility of waiting times looms larger than the disutility of in-vehicle times.However, little has been said about the plausibility of the assumption of compensatory behavior in the preferences forwaiting and traveling. Another open question is whether the variability in waiting and in-vehicle times affects transportdecisions in the same way. To answer these research questions, we conducted a lab experiment with university studentsfrom London, UK and Santiago, Chile. Participants were presented with 14 decisions scenarios that manipulated theaverage and the variability of waiting and in-vehicle times in two bus routes under the choice paradigms of decisions fromdescription and from experience. We found that participants did not compensate waiting and in-vehicle times; rather, theysought to minimize overall journey times. In addition, participants disliked more variability while waiting than traveling.Interestingly, both behaviors were only observed in the experiential choices.

Variance of the outcomes associated with an option oftenprovides a measure of the riskiness of that option. Hence, it isimportant for organisms are able to detect any sudden changesin outcome variance. In Experiment 1, we presented peoplewith graphs of share price time series or water level timeseries. In half the graphs, variance (financial or flooding risk)changed at some point. People were better at detectingincreases than decreases in risk - maybe because it is moreimportant to detect increases in danger than decreases in it.However, in Experiment 2, people were still better atdetecting increases than decreases in variance even whenthose changes did not reflect altered levels of risk. Ourfindings may reflect the fact that the actual change in varianceexceeds the change needed to identify a regime change invariance by a larger amount for upward than for downwardchanges.

Warning labels can be considered as descriptions added to repeated decisions-from-experience. Limited researchso far has looked at the theoretical integration of decisions from descriptions and decisions from experience when the two areavailable concurrently. We explore how the presence and timing of such warning labels influence behaviour. We expected theprovision of warning labels to subsequently reduce risk taking, and that more prior experience before the appearance of suchlabels would lead to stronger habit formation and reduce their behavioural impact. Instead, we show how the appearance ofdescriptions warning against risks can have a perverse effect of increasing risk taking. And counter-intuitively, we also observethat the amount of previous experience prior to the appearance of descriptions does not impact behaviour. Briefly presentedwarning labels also have the same effect as constantly present ones. All of these findings have strong implications on the designof effective warning labels.

People's forecasts from time series underestimate future values for upward trends and overestimate them for downward ones. This trend damping may occur because (a) people anchor on the last data point and make insufficient adjustment to take the trend into account, (b) they adjust toward the average of the trends they have encountered within the experiment, or (c) they are adapted to an environment in which natural trends tend to be damped. Two experiments eliminated the first account: For series that are negatively accelerated or have shallow slopes, people showed anti-damping (the opposite of damping), a phenomenon that cannot be interpreted in terms of under-adjustment. These experiments also produced results consistent with the second account: Forecasts for a given function clearly depended on the other functions that were forecast within the same experiment. However, this second account was itself eliminated by a third experiment demonstrating both damping and, to a lesser degree, anti-damping when people forecast from a single series. We conclude that people have adapted to degrees of growth and decay that are representative of their environment: Damping occurs when trends in presented series are steeper than this and anti-damping occurs when they are shallower. (Contains 5 tables, 10 figures and 7 footnotes.)

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.joep.2005.07.001 Byline: Nick Sevdalis (a), Nigel Harvey (b) Keywords: Evaluability; Preference reversals; WTP Abstract: Consumers' willingness to pay (WTP) can be higher for items that are objectively worse than others when it is difficult to evaluate them comparatively on the relevant dimensions. However, it is unclear how the ease of evaluation affects WTP. In order to investigate the antecedents of WTP, we showed participants an underfilled and an overfilled cup containing the same amount of ice cream or orange juice. We asked them to state their WTP and to report how much they liked the servings (Experiment 1) and how large they judged them to be (Experiment 2). When participants could not evaluate the two cups comparatively, they regarded the overfilled one as fuller and they were willing to pay more for it. This replicates previous work. We also found that, regardless of mode of presentation and cup filling, the desirability of the servings and their perceived size both determined the WTP. However, they did so only when these judgements were made explicitly. This suggests that the influence of product features on WTP depends on their being made salient and that this can be done by asking consumers about them. Author Affiliation: (a) Department of Surgical Oncology and Technology, Imperial College London, 10th floor, QEQM, St. Mary's Hospital, South Wharf Road, London W2 1NY, UK (b) Department of Psychology, University College London, Gower Street, London WC1E 6BT, UK Article History: Received 15 December 2004; Revised 30 June 2005; Accepted 13 July 2005

Purpose. To assess and rank the performance of different methods of predicting the probability of death following a specified surgical procedure. Method. Actuarial estimates of the probability of early mortality [...]