Does the period over which individuals evaluate outcomes influence their investment in risky assets? Results from this study show that the more frequently returns are evaluated, the more risk averse investors will be. The results are in line with the behavioral hypothesis of "myopic loss aversion," which assumes that people are myopic in evaluating outcomes over time, and are more sensitive to losses than to gains. The results have relevance for the equity premium puzzle, and also for the marketing strategies of fund managers.

We report experimental results on the effect of leadership in a voluntary contribution game. Consistent with recent theories we find that leading-by-example increases contributions and earnings in an environment where a leader has private information about the returns from contributing (Hermalin in Am Econ Rev 88:1188-1206, 1998; Vesterlund in J Public Econ 87: 2003). In contrast the ability to lead-by-example has no effect on total contributions and earnings when such returns are commonly known. In our environment the success of leadership therefore appears to be driven by signaling rather than by nonpecuniary factors such as reciprocity.

We examine the force of three types of behavioural dynamics in quantity-setting triopoly experiments: (1) mimicking the successful firm, (2) rules based on following the exemplary firm, and (3) rules based on belief learning. Theoretically, these three types of rules lead to the competitive, the collusive, and the Cournot-Nash outcome, respectively. In the experiment we employ three information treatments, each of which is hypothesized to be conducive to the force of one of the three dynamic rules. To a large extent, the results are consistent with the hypothesized relationships between treatments, behavioural rules, and outcomes.

Informational lobbying -the use by interest groups of their (alleged) expertise or private information on matters of importance for policymakers in an attempt to persuade them to implement particular policies -is often regarded as an important means of influence. This paper analyzes this phenomenon in a game setting. On the one hand, the interest group is assumed to have private information which is relevant to the policymaker, whilst, on the other hand, the policymaker is assumed to be fully aware of the strategic incentives of the interest group to (mis)report or conceal its private information.It is shown that in a setting of partially conflicting interests a rationale for informational lobbying can only exist if messages bear a cost to the interest group and if the group's preferences carry information in the 'right direction'. Furthermore, it is shown that it is not the content of the message as such, but rather the characteristics of the interest group that induces potential changes in the policymaker's behavior. In addition, the model reveals some interesting results on the relation between, on the one hand, the occurrence and impact of lobbying and, on the other hand, the cost of lobbying, the stake which an interest group has in persuading the policymaker, the similarity between the policymaker's and the group's preferences, and the initial beliefs of the policymaker. Moreover, we relate the results to some empirical findings on lobbying.Much o f the pressure placed upon government and its agencies takes the form o f freely provided "'objective" studies showing the important outcomes to be expected from the enactment of particular policies (Bartlett, 1973: 133, his quotation marks).The analysis here is vague. What is needed is an equilibrium model in which lobbying activities have influence. Incomplete information ought to be the key to building such a model that wouM explain why lobbying occurs (information, collusion with decision makers, and so on) and whether lobbying expenses are socially wasteful. (Tirole, 1989: Ch.