The Four "R"s
Taxation has four main purposes or effects: Revenue, Redistribution, Repricing, and Representation.[3]
The main purpose is revenue: taxes raise money to spend on roads, schools and hospitals, and on more indirect government functions like market regulation or legal systems. This is the most widely known function.[3]
A second is redistribution. Normally, this means transferring wealth from the richer sections of society to poorer sections.
A third purpose of taxation is repricing. Taxes are levied to address externalities: tobacco is taxed, for example, to discourage smoking, and many people advocate policies such as implementing a carbon tax.[3]
A fourth, consequential effect of taxation in its historical setting has been representation.[3] The American revolutionary slogan "no taxation without representation" implied this: rulers tax citizens, and citizens demand accountability from their rulers as the other part of this bargain. Several studies have shown that direct taxation (such as income taxes) generates the greatest degree of accountability and better governance, while indirect taxation tends to have smaller effects.[4][5]