Study of the effect of a Financial Transaction Tax on the corporate cost of capital

We study the impact of a Financial Transaction Tax (FTT or Tobin Tax) on the corporate cost of capital. We consider the results on the impact of transaction costs on implied volatility and then use the utility maximization of a market-maker and its asymptotic solution. The FTT impact on volatility, in highly liquid equity option markets, is within two decimals ('the tick value') and is insignificant. The volatility impact is considerable for illiquid option markets especially long-dated equity options, used for the hedging of credit default swaps (CDS). The credit spread increase is computed using a structural model, and amounts between 30 and 60 basis points (b.p). per annum, for 520 year maturities, and a volatility level of 30%. The impact decreases with the corporation leverage ratio. We calibrate from the CDS market the implied volatility for six European corporations and find an increase in spreads by up to 60%. For a corporation with a 343 b.p. 5-year CDS spread, the increase amounts to 174 b.p. On the basis of this sample, the impact we find is between 5 and 20 times higher than the one computed in the study of Lendvai et al. which has been used by European Union authorities to assess the impact on the cost of capital.