… is from page 158 of my Mercatus Center colleague Dan Griswold’s superb 2009 volume, Mad About Trade (footnote deleted):
Import taxes on food, clothing, and shoes fall especially heavily hard on the poor and middle class. The lower a family’s income, the more it will spend proportionally on basic necessities. As the Organization for Economic Cooperation and Development concluded in its study on rich-country farm programs, tariffs on imported food “can bear heavily on low-income consumer households for whom food constitutes a larger share of their total expenditures.” In this way, U.S. trade barriers against farm products act as a regressive tax.