Accounting and the formation of share market prices over time: a mathematical institutional economic analysis through simulation and experiment

This article develops a heterogeneous agents-based model to examine the emergent dynamic properties of share market price formation over time, with a view on financial market stability under alternative accounting regimes. In the model, individual heterogeneous investors interact with each other and with institutional devices which are an accounting system (related to the business firm) and a price system (related to the Share Exchange). These interactions provide mechanisms for transmission through which firm-specific (accounting signal) and market-driven (aggregate price) factors can act. A baseline simulation analysis assesses the financial market stability under three alternative accounting designs, namely two kinds of historical cost accounting regime and one kind of fair-value (mark-to-market) accounting regime. The former prove to better stabilize the financial system in terms of market volatility and exuberance in perfectly balanced conditions between speculative and fundamentalist beliefs and intentions. An evolutionary analysis is then developed by varying the relative degree of speculative attitudes between the two sides of the market. Historical cost accounting regimes further prove to make the financial system more resilient to speculative waves occurring at inter-individual level. Baseline findings are further corroborated through experimental analysis in twelve artificial financial systems. This mathematical institutional economic analysis has general implications for both designing accounting systems aimed at enhancing financial market stability and preventing procyclicality, and the study of accounting information process in the formation of share market prices over time.