One of the most enduring relationships in economics is that proposed by Ernst Engel in 1857: “The poorer is a family, the greater is the proportion of the total outgo [family expenditures] which must be used for food. … The proportion of the outgo used for food, other things being equal is...

The introduction describes the relationship between Rossi-Doria and the United States in the period preceding his first American trip, made in October 1951. In the 1930s Rossi-Doria was already engaged in detailed research on American agriculture; in the postwar period he looked to the United...