This paper shows how the productive interplay of theory and experimental work has furthered our understanding of credit markets in developing countries. Descriptive facts motivated a body of theory, which in turned motivated experiments designed to test it. Results from these experiments reveal both the success and the limits of the theory, prompting new work to refine it. We argue that the literature on credit can be a template research in other domains. Keywords: Credit Markets, Field Experiments. JEL Classifications: O16, C93.