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Preliminary draft prepared for WEIS 2010. Please do not distribute. We introduce and test the hypothesis that control over publication of private information may influence individuals ’ privacy concerns and affect their propensity to disclose sensitive information, even when the objective risks associated with such disclosures do not change or worsen. We designed three experiments in the form of online surveys administered to students at a North-American University. In all experiments we manipulated the participants ’ control over information publication, but not their control over the actual access to and usage by others of the published information. Our findings suggest, paradoxically, that more control over the publication of their private information decreases individuals ’ privacy concerns and increases their willingness to publish sensitive information, even when the probability that strangers will access and use that information stays the same or, in fact, increases. On the other hand, less control over the publication of personal information increases individuals ’ privacy concerns and decreases their willingness to publish sensitive information, even when the probability that strangers will access and use that information actually decreases. Our findings have both behavioral and policy implications, as they highlight how

Theoretical models predict that overconfident investors will trade more than rational investors. We directly test this hypothesis by correlating individual overconfidence scores with several measures of trading volume of individual investors (number of trades, turnover). Approximately 3000 online broker investors were asked to answer an internet questionnaire which was designed to measure various facets of overconfidence (miscalibration, the better than average effect, illusion of control, unrealistic optimism). The measures of trading volume were calculated by the trades of 215 individual investors who answered the questionnaire. We find that investors who think that they are above average in terms of investment skills or past performance trade more. Measures of miscalibration are, contrary to theory, unrelated to measures of trading volume. This result is striking as theoretical models that incorporate overconfident investors mainly motivate this assumption by the calibration literature and model overconfidence as underestimation of the variance of signals. The results hold even when we control for several other determinants of trading volume in a cross-sectional regression analysis. In connection with other recent findings, we conclude that the usual way of motivating and modelling overconfidence which is mainly based on the calibration literature has to be treated with caution. We

We perform an asset market experiment in order to test the central result coming from the new overconfidence models, namely that high levels of overconfidence lead to enhanced trading activity. We find that overconfidence does engender additional trade. Unlike previous experimental or survey-based evidence, ours is the first study to find this to be so when overconfidence is measured using a calibration-based approach that is most akin to the theoretical literature. Further, we investigate the contention that gender influences trading activity through overconfidence. There is no evidence of this, as women have about the same level of both overconfidence and trading activity as do men, and gender is not a useful explanatory variable of trading in a multivariate regression. 2

and other research outputs xDelia final report: emotion-centred financial decision making and learning