Vat: Causes and Consequences

The Value Added Tax: Its Causes and Consequences Michael Keen and Ben Lockwood No 801



The Value Added Tax: Its Causes and Consequences
Michael Keen and Ben Lockwood 1 May 2007

Almost unknown in 1960, the value added tax (VAT) is now found in more than 130 countries, raises around 20 percent of the world’s tax revenue, and has been the centerpiece of tax reform in many developing countries. This paper explores the causes and consequences of the remarkable rise of the VAT. A key question is whether it has indeed proved, as its proponents claim, an especially effective form of taxation. To address this, it is first shown 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 tax ratio. This observation leads to the estimation, on a panel of 143 countries for 25 years, of a system of equations describing both the probability of VAT adoption and the revenue impact of the VAT. The results point to a rich set of determinants of VAT adoption, this being more likely, for example, if a country has a program with the IMF and the less open it is to international trade. In the revenue equation, the presence of a VAT does indeed have a significant impact, but also a complex one, with a negative intercept effect counteracted by positive effects that are greater the higher are per capita income and, more tentatively, openness. While the sign of the revenue impact of the VAT is thus in general ambiguous, most countries that have adopted a VAT seem to have gained a more effective tax instrument in doing so (though this is less apparent in subSaharan Africa), and most without it seem likely to gain from its adoption. JEL Classification Numbers: H20, H21 Keywords: Value added tax; tax reform Authors’ E-Mail Addresses:;

We are grateful to Richard...