摘要：The aim of the paper is to identify the impact of the currency transaction tax on the foreign exchange structure and thus its impact on exchange rate volatility. In a noise trading framework a la Jeanne and Rose (2002), we explain that the exchange rate volatility depends on fundamentals volatility and extra volatility due to the behaviour of noise traders. The exchange rate volatility is lower after introducing a Currency Transaction Tax as it increases the entry cost of noise traders and influences the range of possible equilibria. While there are multiple equilibria of exchange rate volatility without Currency Tax, there are only two aggregate exchange rate volatility corner equilibria after introducing a CTT. One of them is a low exchange rate volatility equilibrium. Moreover, we prove analytically the existence of an optimal tax rate for which the exchange rate volatility depends solely on fundamentals variance. In this case, few noise traders enter the market and there is consequently a low excess volatility
