AS ADAM Smith noted, taxes are often “much more burdensome to the people than they are beneficial to the sovereign.” In America, some have tried to estimate exactly how much more burdensome. The Treasury estimates the total costs of complying with the income tax at about $125 billion a year.

The Internal Revenue Service (IRS) itself is quite lean. Its staff numbers actually fell by 15% between 1993 and 2001. For every $100 it raises in net tax revenue, the IRS costs just 52 cents; its French counterpart costs $1.44, according to the OECD. Adam Smith bemoaned the “frequent visits and the odious examination of the tax-gatherers,” but the chances of being audited by the IRS are much lower than most Americans assume. Jeffrey Owens and Stuart Hamilton, of the OECD, reckon the IRS has only enough auditors to check the books of each American business for one day every ten or 11 years.

The miserly budget of the IRS is, of course, only one part of the total cost of complying with America's tax code. According to a somewhat dated study by Marsha Blumenthal and Joel Slemrod, two respected tax scholars, it takes the average American taxpayer 27.4 hours to file his taxes. But the burden varies greatly. Just under 30% of filers spend less than five hours. These taxpayers perhaps have little cause to hiss.

Besides, all such estimates have to be taken with several grains of salt. Most official estimates are based on a survey that is almost 20 years old. Taxpayers were asked how many hours they spent keeping records, deciphering the tax code and filing their 1983 tax forms. But their answers may have little relevance today. The task of complying with the tax code is now easier (thanks to computers) but also more difficult, because of the code's seemingly organic annual growth in length and obscurity.

The common proxy for this extra difficulty is the number of new words added to the code since the survey was taken (about 500,000). But extra words do not necessarily mean extra complexity. When the Australian government tried to translate its tax rules into plain English it discovered that five lines of code could decompress into as many as five pages of comprehensible prose.

In part, “trouble, vexation and oppression” are the price Americans pay for the tax exemptions, deductions and concessions they cherish so much. As well as raising revenue, America's tax code is charged with inspiring charitable giving, promoting homeownership, defending marriage and delivering pork to the favoured constituencies of ambitious congressmen. If America's tax system asks a lot of its citizens, it may be because they ask a lot of it.