What is the work of economics? How does it operate to establish facts and make them stable? Is it sometimes able to use the world as a laboratory? If so, what measures are necessary to organize the world as a laboratory for economic experiments? To what extent do these measures rely upon the efforts of nonacademic economists, and of other social agents and arrangements including think tanks, government policies, development programs, NGOs, and social movements? A recent “natural experiment” using the social world as a laboratory, carried out in Peru, produced remarkable results, enthusiastically received by economists in the United States and by international development agencies. The paper examines the work of organizing the socio-technical world required to produce this knowledge, the curious kind of facts that were produced, the connections among those involved in this work, in particular the organized work of the neoliberal movement, and the role of the new facts in making possible further efforts at economic experimentation.