We propose a new welfare criterion that allows us to rank alternative financial market structures in the presence of belief heterogeneity. We analyze economies with complete and incomplete financial markets and/or restricted trading possibilities in the form of borrowing limits or transaction...

Traditional finance is built on the rationality paradigm. This chapter discusses simple models from an alternative approach in which financial markets are viewed as complex evolutionary systems. Agents are boundedly rational and base their investment decisions upon market forecasting heuristics....

This papers studies the impact of a financial transactions tax on the trading volume and asset price volatility in a model with heterogeneous beliefs. To model heterogeneous beliefs we follow Kurz (1994, 1997) and restrict the class of beliefs to the subset of rational beliefs. We study a tax...