Limited Information Aggregation and Externalities - A Simple Model of Metastable Market

We analyze a model in which agents’ decisions to enter or exit investments are influenced from their individual and external parties’ transaction histories. Actual investment outcomes are unknown to all participants until the end of decision periods, but outcomes do change depending on the number of participating players in the market and the market’s current state of condition. In this particular model, agents have access to external parties’ information from those who are within their specific social network. Our study of limited information aggregation mainly focuses on market responses to investors’ decisions of exiting the investment. With social structures complicating investment outcomes, we present a model that describes how markets can enter relatively stable statuses long enough for exiting participants to return, which brings the investment back to normal conditions. Our model also supports previous studies that limited information aggregation can cause the exogenous shock effect of global collapse.