AbstractThe economy‐wide economic surplus, defined as output beyond what is needed to sustain the labouring workforce, is one of the oldest ideas in Western political economy. Marx permanently changed economic thinking by characterising it as exploitation. As confidence in government management of economic affairs grew in the twentieth century, how to spend the surplus better than free individuals would spend it themselves became a growing theme among economists and among the broader public. While the role of the surplus in economic theory today is modest, its vibrancy in the public conversation remains.