Securities Transaction Taxes and Market Quality of Equity and Futures Markets: Issues and Evidence

This paper discusses arguments for and against a securities transaction tax (STT) and evaluates the pros and cons based on a review of empirical evidence concerning the impact of STTs on equity and futures markets (i.e., trading volume, bid-ask spreads, and price volatility) and market efficiency in various countries. I find that an STT would likely reduce trading volume and increase trading cost, but may not reduce price volatility. The size of potential STT revenue depends on the STT's impact on market activity. A sizable STT on futures and equity markets would not only fail to generate the expected tax revenue, it would also likely hurt the international competitiveness of US equity and futures markets.