The CTT imposition has started a fresh round of debate on the validity of the STT. Percy Mistry, who has recommended dropping the securities transaction tax (STT) in his report Making Mumbai an International Financial Centre, said on Tuesday, “The STT serves no objective other than the revenue objective of the government. The argument that the STT reduces volatility on the stock exchanges is not borne out by evidence.” On the international experience with STT, Mistry said that since 1980, 40 countries have imposed some kind of transactions tax. Since then, 20 per cent have dropped transaction taxes altogether over the last 10 years while many have reduced them.