Money occupies a powerful place in our lives – it is a problem, a goal, and motivator, a measure of self-worth and national progress, and even an influence on how we relate to each other and to nature – but what happens when communities start to reinvent money and markets? Over the last twenty-five years, grassroots activists in Medellín, Colombia, have used barter markets and community currencies as one strategy to re-weave a social fabric shredded by violence and to establish an economy founded on respect and reciprocity rather than exploitation. In Social Exchange, Brian J. Burke provides a deep ethnographic investigation of this activism and its effects. This story draws us into the cultural and material effects of capitalism and narco-violence, while also helping us understand what new radical imaginations look like and how people bring them to life. The result is an intimate glimpse of urban life in Latin America, as well as a broader analysis of non-capitalist or post-capitalist possibility.