everybody doing what everybody else is doing (2014)

The title is drawn from economist Abjihit V. Bannerjee’s 1992 study ‘A Simple Model of Herd Behaviour’, in which he notes ‘There are innumerable social and economic situations in which we are influenced in our decision making by what others around us are doing. Perhaps the commonest examples are from everyday life: we often decide on what stores and restaurants to patronize or what schools to attend on the basis of how popular they seem to be. … We set up a model in which paying heed to what everyone else is doing is rational because their decisions may reflect information that they have and we do not.’ Such herd behaviour may arise through an information cascade which, as David Easley and Jon Kleinberg note in their book Networks, Crowds, and Markets: Reasoning about a Highly Connected World, ‘has the potential to occur when people make decisions sequentially, with later people watching the actions of earlier people, and from these actions inferring something about what the earlier people know.’ In everyone doing what everyone else is doing, players make selections from a series of actions, judging what to do in response to choices made by others around them.