Economics invents the economy: Mathematics, statistics, and models in the work of Irving Fisher and Wesley Mitchell DANIEL BRESLAU Virginia Tech Abstract. The ‘‘embeddedness’’ of economic life in social relations has become a produc- tive analytical principle and the basis of a penetrating critique of economic orthodoxy. But this critique raises another important, social and historical question, of how the economy became ‘‘disembedded’’ in the ¢rst place ^ how the multitude of transactions designated (somewhat arbitrarily) as economic were abstracted from the rest of social life and reconstituted as an object, the economy, which behaves according to its own logic. This article investigates the social sources of some innovations in economic thought that contributed to the emergence of the economy, particularly statistical indicators and mechanical models. By examining the rede¢nitions of the object of economic research developed by Irving Fisher and Wesley Mitchell in the 1890s and the ¢rst decades of the twentieth century, I argue that the abstraction of the economy from the remainder of social life was a strategy linked to the position of these innovators within the ¢eld of economics, conceived as a social structure. Possessing a specialized scienti¢c cultural capital, but lacking upper class background, contacts, and disposi- tions that characterized the founders of academic economics, Fisher and Mitchell elaborated new de¢nitions of their discipline’s object of study, and a new type of economic expertise. The economy is a strange kind of object. On one hand, it seems to be as objective and concrete as any physical object that we encounter. It is routinely described as a thing that behaves independently of anyone’s will and with which we are forced to live. One issue of the Wall Street Journal attaches the following verbs to the economy: ‘‘expanding,’’ ‘‘falling,’’ ‘‘gaining steam.’’ The same paper tells us that the economy can be ‘‘sharply divided,’’ ‘‘strong,’’ or ‘‘stable.’’ An economy can be good or bad, healthy or sick, and plays a decisive role in politics: ‘‘It’s the economy, stupid.’’ A nominalist might argue that this is simply a metaphor, a rei¢cation, or simply a rhetorical convenience that would not appear in serious, self-critical discourse. But if we open any macroeconomics textbook we ¢nd that the experts tend to be more extreme realists than the rest of us, de¢ning their object of study as ‘‘the performance of the economy.’’ 1 Theory and Society 32: 379^411, 2003. ß 2003 Kluwer Academic Publishers. Printed in the Netherlands.