Security Transaction Taxes and Long-Term Volatility

Abstract: The impact of Security Transaction Taxes (STTs) on the financial market has been studied by authors for decades, showing mixed results between positive, negative, or insignificant relations between STTs and financial volatility. This thesis adds a new approach to previous studies by taking an innovative long-term approach to the topic, analysing the effect of both the New York State STT (1905 – 1981) and the United States STT (1914 – 1966) on volatility in the New York Stock Exchange (NYSE) and NASDAQ as measured by the S&P500 Index. The period of investigation is from 1950 to 2019. This analysis reveals a negative relation between the NY STT and volatility when those are computed in long periods of time, implying that the presence (and increase) of STTs lead to a reduced volatility in the financial market. When breaking the analysis down into shorter periods of time the relationship between STTs and financial volatility proved to be insignificant. At the same time, the US STT is not statistically significant neither in the long-term nor in any of the separated shorter analysed periods. This thesis therefore highlights the relevancy of performing long-term studies rather than short-term ones which has been the focus of previous research.