In 1993, after five years of grad school and low-wage postdoctoral research, Michael Kremer got a job as a professor of economics at MIT. With his new salary, he finally had enough money to fund a long-held desire: to return to Kenya’s Western Province, where he had lived for a year after college, teaching in a rural farming community. He wanted to see the place again, reconnect with his host family and other friends he’d made there.
When he arrived the next summer, he found out that one of those friends had begun working for an education nonprofit called ICS Africa. At the time, there was a campaign, spearheaded by the World Bank, to provide free textbooks throughout sub-Saharan Africa, on the assumption that this would boost test scores and keep children in school longer. ICS had tasked Kremer’s friend with identifying target schools for such a giveaway.
While chatting with his friend about this, Kremer began to wonder: How did ICS know the campaign would work? It made sense in theory—free textbooks should mean more kids read them, so more kids learn from them—but they had no evidence to back that up. On the spot, Kremer suggested a rigorous way to evaluate the program: Identify twice the number of qualifying schools as it had the money to support. Then randomly pick half of those schools to receive the textbooks, while the rest got none. By comparing outcomes between the two cohorts, they could gauge whether the textbooks were making a difference.