Policy Documents

Would a Financial Transaction Tax Affect Financial Market Activity? Insights from Futures Markets

George H. K. Wang and Jot Yau –
July 9, 2012

In the wake of the recent financial crisis, several commentators have suggested a transaction tax on financial markets. The potential consequences of such a tax could be hazardous to the financial markets affected as well as to the economy. In this paper, we review the relevant theoretical and empirical literature and apply our findings to estimate the possible impact of a transaction tax on U.S. futures market activity as well as its utility as potential tax revenue.

We find that the impact of a transaction tax on market activity (trading volume, bid-ask spread, and price volatility) will determine the potential of such a tax as a source of government revenue. We also find that the current estimated elasticity of trading volume with respect to a transaction tax in the U.S. futures markets is much higher than those reported in the extant literature and those used by the government in such computation. We show that a transaction tax on futures trading will not only fail to generate the expected tax revenue, it will likely drive business away from U.S. exchanges and toward untaxed foreign markets.

A review of the literature and estimates contained here indicates that there is an inverse relationship between transaction cost (bid-ask spread) and trading volume; to the extent that a transaction tax increases costs, trading volumes will likely fall. There is also a positive relationship between transaction cost and price volatility, suggesting that the imposition of a transaction tax could actually increase financial market fragility, increasing the likelihood of a financial crisis rather than reducing it. Perversely, the imposition of a financial transaction tax could have results that are exactly the opposite of those hoped for by its proponents.