The price of maize in Kenya and the rest of east Africa has hit the roof. The wider Horn of Africa region is currently experiencing its worst drought in 60 years, with thousands of refugees streaming into Kenya from Somalia every week.

10 million people in the wider Horn of Africa region are at risk. Kenya is already planning on opening a third refugee camp (besides Dadaab and Kakuma) to accommodate Somali refugees fleeing the famine.

Africa is the last major world region yet to experience a green revolution. Subsistence agriculture, in my view, is the culprit. Governments in the region must seriously come up with plans to consolidate and commercialize agriculture asap.

Having upwards of 70% of people dependent on subsistence agriculture is simply not sustainable. Period. To paraphrase Adam Smith, specialization determines the extent of the market AND the complexity and size of the economy. [italicized text mine]

As the region mulls over its agriculture and food policy it might help to consult Nunn and Qian’s new paper in the latest QJE. The paper makes the argument that the potato beats most of the Old World staples as far as a balanced supply of nutrients and calories is concerned (p. 604-5).

Maize is unable to rival potatoes in terms of nutrients or calories. It produces significantly fewer calories per acre of land. Moreover, humans are unable to subsist on a diet that is too con- centrated in maize. Significant consumption of maize is associated with pellagra, a disease caused by niacin deficiency. The effects of pellagra include skin, digestion, mental disorders, and, if un- treated, eventual death. The disease was first observed in the 1730s in Italy and even today continues to affect poor populations with diets that rely too heavily on maize. A second adverse effect of a corn-heavy diet is protein deficiency (Messer 2000a).

Sweet potatoes are also nutritious and produce similar amounts of calories per acre of land as potatoes, but they differ from potatoes in two important ways. First, the archaeological evidence suggests that sweet potatoes, transported by Polynes- ians, reached the Old World long before the European discovery of the New World. For many countries in our sample, their impact would have been felt as early as 1000 (Hather and Kirch 1991). Second, a close substitute to the sweet potato, the yam, already existed in the Old World (O’Brien 2000). Yams are broadly simi- lar to sweet potatoes in terms of both nutritional content and the requirements for cultivation. Many regions that were suitable for cultivating sweet potatoes had already cultivated yams when the former were introduced.

The New World staple, cassava, which is also called manioc or yuca, also provides abundant calories. But its deficiency in pro- tein and other important nutrients causes it to be a less “complete” food than potatoes (Cock 1982). In addition, because cassava con- tains toxic cyanogenic glycosides (e.g., cyanide), failure to properly prepare cassava causes konzo, a neurological disease that causes paralysis.