“Throughout the 1980s, immigrants fled civil wars in Central America. When they arrived in the United States, their asylum claims were frequently denied. They found themselves deported back to war zones. Some Americans found this unacceptable. More than 70,000 Americans from multiple cities and religious denominations participated in the Sanctuary Movement, a political and religious movement that defied federal immigration laws. How do you get so many people to cooperate on such a risky project? Using the tools of economics, we can better understand how this social movement worked.”