How taxes changed

Taxing what can be counted

Early taxation is the history of what an administration could actually observe. A field can be paced out. A harvest can be watched. A house has a countable number of hearths, and at one point in England a countable number of windows, which is why certain old buildings have windows that were bricked up. None of these things measure wealth well. They were used because they could be verified by a person standing outside with a notebook.

The same logic explains the enormous historical importance of customs duties. Goods crossing a border have to pass a physical point, and a physical point can be staffed. For centuries, a large share of state revenue in trading nations came from goods arriving at ports, not because trade was thought to deserve taxing but because trade was the part of the economy a state could reliably see.

Excise, and taxing the making of things

Excise duties, charged on goods produced within a country rather than imported, extended the same principle inland. Brewing, distilling, salt-making and tobacco-processing all happened in identifiable premises with identifiable output, so they could be measured and charged. Excise was frequently resented in a way customs was not, because it put officials inside domestic businesses, and several significant political conflicts in early modern Europe and colonial America grew directly out of that intrusion.

Excise also produced the first serious arguments about what is now called behavioural taxation: the observation that a duty heavy enough to raise money is usually also heavy enough to change what people buy. Those two goals pull against each other, since a tax that successfully discourages a habit eventually stops raising money from it.

Income tax arrives, usually during a war

Taxes on income appeared late and almost always under pressure. The pattern repeats across countries: a war creates a need for revenue far beyond what duties can supply, an income tax is introduced as a temporary emergency measure, and it turns out to be too useful to remove. Britain's first income tax was introduced during the wars with France at the end of the eighteenth century, repealed afterwards, and reintroduced within a generation. Comparable stories exist elsewhere.

What made income tax workable was not the idea, which is obvious, but the administration. Charging a share of what someone earns requires knowing what they earn, and that requires either an honest declaration that can be checked or an employer who reports it. As paid employment by large organisations became the normal way to earn a living, the second option became practical on a national scale, and modern income taxation followed.

Deduction at source, and the tax you never handle

The single most consequential administrative invention in the history of taxation is probably deduction at source: requiring the payer, rather than the recipient, to hand the tax over. It transformed collection rates, because the money never reaches the person who would otherwise have to part with it, and it transformed the politics of tax, because a deduction that appears on a payslip is far less visible than a bill that arrives once a year.

The same insight underlies the spread of value-added taxation from the middle of the twentieth century onwards. Rather than charging once at the final sale, where evasion is easiest, a value-added tax collects a fragment at every stage of production, with each business claiming back what it paid on its own inputs. The arithmetic reaches the same destination as a simple sales tax, but the paper trail is self-policing, because each business has a direct interest in documenting what it was charged.