Demography

You Are What You Eat

See allHide authors and affiliations

Science  29 Jul 2011:
Vol. 333, Issue 6042, pp. 501
DOI: 10.1126/science.333.6042.501-a
CREDIT: FOTOSEARCH

Potatoes were brought to the Old World from South America at the end of the 16th century. The total population of the Old World and the movement of people from farms to cities increased severalfold between 1700 and 1900. In order to assess the extent to which the former contributed to the latter, Nunn and Qian have analyzed Old World historical data and focused on two kinds of variation: the times at which potatoes were introduced and the places at which geophysical conditions were well suited for potato cultivation. The balanced nutrients and calories supplied by the potato explained its value as a subsistence crop, especially in comparison to other staples such as wheat, oats, and barley (the recent deciphering of its genome by the Potato Genome Sequencing Consortium may lead to the development of disease-resistant varieties). Equally important, much of Europe was well placed to offer a favorable growing environment, and the authors attribute 20 to 30% of the increase in population and urbanization to the introduction of the potato. Urbanization reflected the improved productivity of agriculture and the subsequent transfer of labor from farms to cities, which in turn promoted economic growth.

Q. J. Econ. 126, 10.1093/qje/qjr009 (2011); Nature 475, 189 (2011).

Navigate This Article