Smith on Taxation and Public Finance
Adam Smith laid out four famous canons of taxation that remain the foundation of modern tax policy debates.
The Four Canons of Taxation
In Book V of The Wealth of Nations, Smith proposed four maxims that every tax system should satisfy. First, equity: subjects should contribute in proportion to their ability to pay. Second, certainty: the tax owed should be clear, not arbitrary. Third, convenience: taxes should be collected at the time and manner most convenient to the contributor. Fourth, economy: the cost of collection should be minimized relative to what the tax brings in.
These canons were not abstract ideals. Smith drew on decades of observing British and European tax systems that routinely violated all four principles. Tax farmers in France, for example, extracted far more from citizens than ever reached the royal treasury, and the uncertainty of obligations left ordinary people at the mercy of corrupt collectors.