The Impact of the Tobin Tax in a Heterogeneous Agent Model of the Foreign Exchange Market

In this thesis, we assess the impact of the Tobin tax on key statistics of exchange rate returns with use of a heterogeneous agent based model. The answer to the question of how transaction costs affect exchange rate dynamics is not only interesting from a theoretical point of view but also has practical implications as several regulators are contemplating imposition of such a tax nowadays. Motivated by the recent research showing the great importance of the mar- ket micro structure, we choose to explore the impact of the tax in a market cleared by the Walrasian auctioneer. This settings, as we argue, could resem- ble the two layered structure of the real foreign exchanges more closely than a price impact function which is often adopted in studies regarding the Tobin tax. To assess the impact of the tax, we extend the model of De Grauwe & Grimaldi (2004) by the inclusion of transaction costs. The original model con- sists of boundedly rational agents who use a blend of fundamental and technical analysis to predict the future exchange rate. An ongoing competition between the forecasting rules creates chaotic price movements not dissimilar to the ones observed in the real foreign exchanges. We use computational methods to assess the effect of the Tobin tax within the model and find that the Tobin tax is..