Has the VAT proved, as its proponents claim, an especially effective form of taxation? To address this, this paper first shows that a tax innovation-such as the introduction of a VAT- reduces the marginal cost of public funds if and only if it also leads an optimizing government to increase the...

This paper estimates the tax-price elasticity of giving using UK administrative tax return data, exploiting variation from a large tax reform. We estimate both the intensive and extensivemargin elasticity, using a novel instrumental variables strategy. Then, we derive new conditions to evaluate...