Historians have long sung the praises of the potato when talking about the boom in population and urbanization we saw in the 18th and 19th centuries. Potatoes are packed with vitamins and minerals—including, importantly, vitamin C—and can be grown on less land with less labor than wheat, barley and oats. When the potato showed up in the Old World around 1700, it was a very big deal. How big? Well, two economists recently tried to quantify how much credit we should give to the potato for its hand in this:

The answer, according to Harvard’s Nathan Nunn and Yale’s Nancy Qian, is quite a lot. The researchers looked at data for 132 Old World countries and, taking into account the percentage of land that was suitable for potato farming, found that 22% of the increase in population growth after 1700 could be attributed to the potato. The two time periods we’re comparing here are 1000-1700 and 1700-1900—and we’re talking about increase in population growth, not the increase in the raw number of people.

Potatoes really helped out with urbanization, too. Nunn and Qian find that the introduction of the potato explains 47% of the post-1700 increase in the average urbanization rate.

The present-day take-away perhaps has less to do with potatoes specifically and more to do with the general importance of farming when we go to do things like try to help less-industrialized countries increase standard of living. Nunn and Qian write:

These results show that food and nutrition matter. By increasing the nutritional carrying capacity of land they can have large effects on population. To the extent that urbanization serves as a measure of the shift from rural agriculture to urban manufacturing, our estimates also provide historic evidence of the importance of agricultural productivity for economic development… Our estimates suggest that increased agricultural productivity can play a significant part in promoting the rise of urban centers, industry, and economic development.

Barbara!