A single experiment does not provide a final answer on whether a program would universally “work.” But we can conduct a series of experiments, differing in either the kind of location in which they are conducted or the exact intervention being tested (or both). Together, this allows us to both verify the robustness of our conclusions (Does what works in Kenya also work in Madagascar?) and narrow the set of possible theories that can explain the data (What is stopping Kennedy? Is it the price of fertilizer or the difficulty of saving money?). The new theory can help us design interventions and
...more
