Written for the RENUA flat taxes event today.
When all the little economists are in short pants, we learn the principles of public finance. Governments have to tax households and firms in order to provide services the market won’t, like libraries, street lighting, and national defense, as well as redistributing income from the rich to the poor as an aid to social solidarity. Taxes are a necessary evil. All taxes induce distortions to people’s behaviour. Some distortions, like the plastic bag tax, are clearly good. They make almost no one worse off and make lots of people better off. Recurrent taxes on property are in fact the least distortive to long run GDP per capita we have. While a site value tax would have been perfect, the LPT does a similar if suboptimal job.
Some taxes are highly distortionary, such as a very low corporation tax rate, or a very high income tax rate. These make lots of people better (and worse) off and damage important incentives. An efficient tax structure would deliver the funds to power public services with the minimum of distortions to individual and collective incentives. The theory of public finance has come around to the view that marginal taxes are not the most important thing to worry about, in information-opaque systems, the average tax rate should be relied on most heavily. The all-in tax rate for personal income tax & employee social security contributions is 52% here, relative to 46% on average across the OECD.
Perhaps more importantly, the ability to balance the average tax rate with a corruption-resistant tax structure through which taxes are collected and disbursed is a major asset of any public finance structure. Important results have now been established showing the spread of corruption is quite badly affected by the ease with which the variables which determine the tax base can be manipulated by those in power. If we worry about the Noonan-end of the tax gathering element first, then, two principles which therefore make sense are simplicity and certainty with respect to the tax system.