The centre-left Progressive Policy Institute sends a weekly email called “Trade Fact of the Week”. This week’s edition says that tariffs are the United States’ most regressive tax, getting most of their revenues on life’s essentials and cheap consumer goods. Tariffs therefore hurt poor families more than anyone else. Tariffs only generate £25bn in revenue, but clothes bring in £9bn of that, shoes £2bn, and food £600m. Cheap household goods like towels, drinking glasses, cutlery bring in an additional £2bn. The PPI points of that while imports of life’s necessities and mundane consumer products make up about 10 percent of imports, they actually raise around 60 percent of tariff revenue.

Taking Consumer Expenditure Surveys from the Bureau of Labor Statistics, the PPI shows that:

a typical top-ten-percent family spent about 4.4 percent of its pre-tax income on food and clothes (excluding alcohol and restaurant meals) in 2005, and the comparable bill for a single-parent family was 15.8 percent of income. Any flat tariff on shoes and clothes, therefore, would hit single moms about three times as hard as rich families. The actual tariff system is not flat, though, but steeply tilted against poor people, as tariffs are systematically high on cheap products but low on luxury goods. Sterling silver forks, for example, have no tariff while cheap stainless steel forks get 20 percent. A long-sleeved men’s silk shirt has a 1.1 percent tariff and its polyester equivalent 25.9 percent; silk brassieres get 2.7 percent, while cotton and polyester bras get 16.9 percent.

And the regressive nature of import tariffs is another reason why campaigners like Christian Aid are wrong in their frankly bizarre support for tariffs on food in developing countries. Far from helping poor countries develop, tariffs on food and other essential items cause malnutrition and lock poor people in chains of poverty. Like in the United States, tariffs in developing countries protect vested interests at the expense of the people as a whole, hurting the poorest the most.