Between 1700 and about 1950, world populations began to skyrocket. This growth was fastest in Northern Europe, and coincided with both an increase in city population share and Northern European world-dominance. There are clearly many reasons why this happened, but one powerful argument suggests that it was the simple potato that played the largest role.
Population increase can be due to both an increase in fertility and or a decrease in mortality. In Northern Europe, decreases in fertility after 1820 were more than offset by the larger decreases in mortality. Although hygienic advances played a major role, the main contributing factor was likely improved nutrition. Importantly, Fogel showed “an enormous increase in caloric intake after the middle of the eighteenth century, measured both directly, from agricultural output and diary surveys, and indirectly through changes in adult height.”
Although often not thought of as a daily part of your balanced breakfast, potatoes are incredibly nutritious. A medium potato contains 45% of your daily vitamin C, 18% of your potassium, 26% vitamin B6, and significant amounts of thiamin, phosphorous, iron, zinc, and an amount of fiber equivalent to that of other cereals such as wheat. In fact, a diet a of potatos and milk/butter is enough to live “healthily” on. Since potatoes have such a higher density of calories than comparable grains – an acre of land can support roughly 10,000 calories of wheat, barley, or oats versus 32,000 calories of potatoes – that families were able to sustain themselves on much smaller parcels of land. A family needed only an acre of potatoes and a single milk-cow to be self-sufficient.
Other factors drove the adoption of potatoes. They could be easily stored in winter, and concomitantly fed to livestock which implies increased availability of meat. Also, potatoes could be discreetly buried. Advancing armies usually demanded local stores of grains for food, causing mass starvation. Since they were hesitant to start digging everywhere up, burying of potatoes allowed increased survival for local peasants. This helps explain why the proportion of land dedicated to potatoes increased after every major war (up to, and including, World War II).
A recent study analyzed potato growth in order to determine the effects of the introduction of the potato across the Old World (all of the non-Americas). They found that the potato accounts for 12% of the increase in population, 22% of the increase in population growth, 47% of the increase of urbanization, and 50% of the increase in urbanization growth. It is astounding that something as small as the introduction of a potato can be such a large positive shock to the population.