**3.1 Payoff function and signals**

An unknown number Y is selected randomly from a range of values {10, 11..., 90}. Players do not know this number but have to guess it based on two types of information (signals). The first signal is public (Pu), common to all players in the same game session. The second is private (Pr). It is specific to each subject (player). Both signals are randomly selected from the same interval [Y-10, Y + 10]. The decision consists of choosing between a safe action A that brings a fixed payoff T or a risky action B that generates a payoff Y under certain conditions:

	- 20 in stage 1 of sessions 1 and 2 and in stage 2 of sessions 3�<sup>5</sup>
	- 50 in stage 2 of sessions 1 and 2 and in stage 1 of sessions 3�<sup>5</sup>

• **0**, otherwise.
