This project examines the creation and consequences of social memory. Social memory refers to beliefs about past behavior created by communication across generations in an ongoing society. Since individuals do not live forever, and since written and oral accounts of the past can be manipulated, social memory need not be accurate or credible. Yet, accountability of people and their governments requires some knowledge of the past.
This project examines the nature of social memory, how it is created, and what are the consequences. It builds on a model of dynastic games developed by the researchers. Dynastic games are infinite horizon games with periodic, generational replacement. Each dynasty is a succession of short-lived individuals, each of whom cares about the well being of his successors, and each has no direct knowledge of the past before his entry. Past behavior is therefore communicated by members of one generation to the next.
The older generation's incentives to accurately communicate the past, and the younger generation's beliefs about what is communicated are the central objects of concern. The project demonstrates how various anomalies can arise: (a) it is very possible for equilibrium beliefs--hence social memory--about the past history of events to be wrong; (b) accurate social memory may paradoxically entail dubious beliefs; (c) social memory is sometimes deliberately erased, the results of which can beneficial.
Results so far establish that social memory surpasses full or direct memory in terms of outcomes that can be sustained. In fact, some efficient outcomes that could not be sustained under full memory are sustainable under social memory. Two broad areas of inquiry are therefore proposed. First, the project investigates the formal relation between social memory and beliefs about unanticipated messages (i.e., "mistakes"). Social memory emerging from a "trusting" society appears quite different than that from a "skeptical" one. The consequences of each are examined. Second, the deliberate erasing of memory and its consequences are examined.
Dynastic games are natural models of ongoing societies--they are an important complement to models with infinitely lived agents in terms of both theory and relevance. Results indicate that the two types of models behave quite differently. However, little is known about social memory or about dynastic games generally. The project fills a critical gap in the literature since standard models concern whether individuals learn about present fundamentals, whereas this project concerns whether social memory encodes the past. The project makes explicit the connection between equilibrium beliefs and social memory, and between social memory and equilibrium outcomes. Finally, the research team has expertise with game theoretic models of communication, as well as substantial breadth in areas of social norms, legal systems and political institutions.
Broader impact. Social memory has enormous implications for conflicts around the world. In some conflicts those who control access to information manipulate social memory. In other conflicts, recipients of truthful information doubt its credibility. Those most vulnerable to these problems are usually underrepresented groups excluded from social and economic elites. The project enhances our understanding of these problems by showing how they arise as equilibrium phenomena.
