Overall, the dogmatic argument that a financial transactions tax is unworkable is clearly false. It operates in a lot of countries. The wide-eyed hope that such a tax can be a truly major revenue source also seems to be false. In part because of concerns over the risk of creating counterproductive incentives–either just to structure transactions in a way that minimizes such a tax or even to react in a way that reduces liquidity and increases volatility in financial markets–the rate at which such taxes are set is typically pretty low. As the authors write, “the idea that an FTT can raise vast amounts
of revenue—1 percent of gross domestic product (GDP) or more—has proved inconsistent with actual experience with such taxes.”
The question with any tax is not whether it is perfect, because every real-world tax has some undesirable incentive effects. The question is whether a certain tax might have a useful role to play as part of the overall portfolio of real-world taxes. For what it’s worth, this particular review of the evidence leaves me skeptical that expanding the currently existing US financial transactions tax from its very low present level would be a useful step.
That is from Timothy Taylor.