How should we understand economies in a moment of profound social, technological, and ecological disruption? For more than a century, three perspectives have dominated. Neoclassical economics treats the economy as a system governed by its own laws; Marxism, as a mode of production dominated by class; much of economic sociology, as a domain embedded in society. Despite their rivalries, all three assume that "the economy" simply exists, out there waiting to be explained. Economization breaks with this assumption and offers a bold alternative. Instead of asking what the economy is, Michel Callon, Koray Caliskan, and Donald MacKenzie ask how things become economic in the first place. Nothing is economic by nature-not even markets. Humans are not the only agents that shape economic life: computer programs, oceans, sciences, and even viruses take part in creating value and exchange. Through analyses of markets and digital platforms, this book presents a new way to understand contemporary economies, showing how market exchange relates to gift and barter. Each chapter ends with a practical guide to help readers apply this approach. Finally, Economization argues that we must remake our economies to keep the Earth habitable. Moving beyond greening markets and ecological economics, it identifies an emerging form-ecologization-that reorients economic life around care, interdependence, and the transport of value across human and nonhuman worlds. Social scientists have long helped make economies; the point now is to help ecologize them.