I've been reading about proposals for a "financial transaction tax" on high-frequency stock market trading. The idea is to curb speculative volatility and raise revenue, but critics say it would just reduce liquidity and hurt ordinary investors' retirement funds. I'm curious if there's any real-world data from places that have tried a small version of this, and what the actual impact was.
France's 2012 securities transaction tax cut turnover on taxed stocks; liquidity fell but volatility wasn't clearly affected; the design targeted large firms and DI differences show turnover drop.
Italy's 2013 Tobin tax trial saw trading volumes plunge as investors moved to other markets; early warnings from analysts warned revenue would be weak.
Sweden's 1984 FTT caused a big share of volume to migrate to London; volatility didn't notably drop, and revenue was far below expectations.
UK stamp duty evidence suggests prices adjust to tax levels (capitalisation) but volatility remains largely unchanged.
Bottom line: real world tests tend to reduce liquidity and trading activity with mixed or modest impact on volatility; revenue tends to be overestimated; the policy debate remains lively.