Abstract (EN)

The dissertation reviews the effects, on capital markets, of implementing, within the EU, an excise tax (the FTT) on all financial transactions. We review the effects on the volatility, the liquidity, trading volumes and the price of assets. In Chapter I, we analyze the option market-makers hedging strategies. We conclude to an insignificant effect of the FTT in highly liquid options markets, as opposed to a significant effect in low liquid option markets, the maximum being reached when market makers hold positions until their expiration date. Chapter II evidences a negative impact of the FTT on the corporate cost of capital due to the illiquidity of long dated option markets, and the arbitrage between equity and credit derivatives. The FTT would increase considerably the cost of capital of European companies whose main competitors are outside the EU.In Chapter III, we model both stocks and bonds theoretical prices and conduct simulations of their reaction to the introduction of the FTT. We find that both shares and bond prices will be negatively affected by the FTT, increasing the cost of capital, in the short and long run. Companies with high leverage and a low tax rate will see the price of their shares fall further than the price of shares of comparable, high-tax, leveraged companies. This suggests that EU should level all corporation tax rates, within the EU, prior to the introduction of the FTT. Finally, the FTT has an antagonistic effect to the Basel III regulation which seeks to increase the capital of banks, because at the same time it lowers the prices of securities issued by Banks. In conclusion, our original approach focusing on options, is fruitful. It makes possible to quantify the impact of FTT on volatility and allows a theoretical justification of the negative impact on asset prices found in empirical reviews of past experience of the introduction of a FTT.