This paper characterizes the optimal transaction tax in an equilibrium model of financial markets. If investors hold heterogeneous beliefs unrelated to their fundamental trading motives and the planner calculates welfare using any single belief, a positive tax is optimal, regardless of the magnitude of fundamental trading. Under some conditions, the optimal tax is independent of the planner's belief. The optimal tax can be implemented by adjusting its value until total volume equals fundamental volume. Knowledge of (i) the share of nonfundamental trading volume and (ii) the semielasticity of trading volume to tax changes is sufficient to quantify the optimal tax.

中文翻译：

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最佳金融交易税

本文描述了金融市场均衡模型中的最优交易税。如果投资者持有与其基本交易动机无关的异质信念，并且规划者使用任何单一信念计算福利，则无论基本交易的规模如何，正税收都是最优的。在某些情况下，最优税收与计划者的信念无关。最优税收可以通过调整其价值来实现，直到总量等于基本量。了解 (i) 非基本交易量的份额和 (ii) 交易量对税收变化的半弹性足以量化最优税收。