“…First, it is easy to use because it has only one free parameter ( ). Second, parameters in self-tuning EWA naturally vary across time and people (as well as across games), which can capture heterogeneity and mimic 'rule learning' in which parameters vary over time (see, for example, Stahl, 1996Stahl, , 2000Salmon, 1999). For example, if rises across periods from 0 to 1 as other players stabilize, players are effectively switching from Cournot-type dynamics to fictitious play.…”