While attention has, appropriately, been focused on getting food and medicines to the victims of the famine in the Horn of Africa, many observers are asking about longer-term solutions, especially if droughts such as the current one become more frequent with climate change. One possibility is to expand irrigation.
Currently, only about 4 percent of Sub-Saharan Africa’s arable land is irrigated; the rest is rain-fed, meaning it is susceptible to droughts and floods. Yet, irrigated land can have yields that are up to five times those of rain-fed areas. It must be the case that the costs of irrigation—capital, recurrent, administrative, political—are sufficiently high to outweigh these benefits. But if you take into account the possibility of more frequent floods and droughts, which would make irrigated land relatively more attractive, does the benefit-cost calculation change?