As Mary Morgan points out in the foreword to this book, econometrics is usually regarded as a creation of the twentieth century. The field was institutionalized in the 1930s, on the basis of concepts and techniques worked out in the 1910s and 1920s. If, however, we define econometrics more loosely as an endeavor to bring economic theory into accord with statistical facts, then the Econometric Society had predecessors going back at least a century earlier. Philippe LeGall aims simultaneously to plumb this deeper history and to contrast the practice of econometrics in the nineteenth century with its dominant form in the twentieth. The “models” of his title belong to the modern version of econometrics, with its reasoning from simplified and, in that sense, artificial constructions anchored in economic theory rather than in a faith in natural order. “Nature” refers here to a lawful world tending to equilibrium, in which a quantified theory can be derived from patterns in the statistics. The two epochs are separated, he suggests, by a rift in world view, the loss of determinism accompanying the “probabilistic revolution.”

While the title and the contents offer us a book about France, LeGall does not insist on important distinctions of place. W. S. Jevons, in particular, is, for him, cut from the same cloth as the three French writers he examines in the first half of the book. And the French proto-econometricians themselves, as it seems to me, are quite disparate. A. A. Cournot, the earliest, was an esteemed though not illustrious philosophical and economic author in his own day, and in the late nineteenth century won respect and even admiration from the proponents of marginal economics in its mathematical form. In France, especially, he is now more prominent than ever, and his main works have been republished in a new critical edition. Cournot knew his way around in the world of mid-nineteenth-century French science. The other two authors treated by LeGall have radically different profiles. Jean-Edmond Briaune (1798–1885), who studied law and then made his career in agronomy, was largely unknown to the history of economics until a few years ago. His publications are about grain prices, seemingly with little direct reference to the field of political economy. His twentieth-century obscurity perpetuated a lack of reputation in his own day, and he seems not to have been connected with the elite of savants or economists. The last member of this French trio, Jules Regnault, was an investor from Belgium who sought out reliable cycles of stock prices. Like Briaune, he was not known to the economists of his day, and he did not situate his work in reference to theirs. He did take an interest in science, especially statistics, and drew regularly on ideas of that highly quantitative Belgian, Adolphe Quetelet.

LeGall's historical interpretation does not presume that these three men knew or even knew of one another. He sees them, indeed, as uncommon and rather isolated figures, yet not as pure oddities existing outside of history. He portrays here not an intellectual movement but intellectual moves that can be situated within particular “conditions of possibility.” Those conditions he identifies with a nineteenth-century scientific world view, one in which God has created a natural order, accessible to man, that extends also over human affairs. The “nature” that underlay the nineteenth-century econometric efforts is I think a fluid and multifarious thing. LeGall invokes it whenever Briaune or Regnault point to meteorological and astronomical effects on crop yields and hence on prices, but also whenever they assert the possibility of real, deterministic knowledge, or of a steady state to which the world is tending. Perhaps he demands too much of natural knowledge, for nineteenth-century science was famously divided over such fundamental questions as the relation of divinity to the order of nature. Natural science and political economy engaged in overlapping discourses with no consensus in sight about progress, decline, and the steady state. Also, Briaune and Regnault may not have been closely aware of contemporary scientific discussion. And yet I think LeGall is right that they anchored their arguments in what they understood to be the methods and implications of the science of their day. At least it is noteworthy that Briaune and Regnault relied very little on specifically economic forms of understanding—based for example on rational individuals pursuing their interests, factors of production, social classes, or the new organization of work into factories powered by steam. Rather, they looked for regularities in their numbers, guided by a doctrine of empiricism and of law. They based their analyses on tables of numbers characteristic of the rising field of statistics, and often also on graphical reason.

Graphs and numbers are what they most conspicuously shared with the generation of the twentieth century that invented a more recognizable version of economics. LeGall writes specifically about Lucien March, who became head of the French statistical office in the early twentieth century, and Marcel Lenoir. Both March and Lenoir studied with sufficient success at the elite and highly mathematical Ecole Polytechnique to enter the still more elite Corps of Mines. March translated the third edition of Karl Pearson's Grammar of Science, and shared Pearson's commitment to statistics and eugenics. The philosophy, though, is more pertinent here. March, echoing Pearson, put his faith in the quantitative methods of science, not as a way to uncover the true causes embedded in natural processes themselves, but as useful tools deployed by needful humans to get a grip on the complexity of the world. He was suspicious of simple theories that claimed too much. Unlike Pearson, who insisted on the continuities between natural and social science, he emphasized the contrast between the experimental control of the laboratory and the teeming causes of the social and economic world.

One of the very best features of this book is the contrast between March and Lenoir, each of whom was seeking strategies to comprehend complexity. Whereas March's preferred tool was the graph, whose dips and peaks preserved the irregularities of the world, Lenoir's was the model. His models simplify on the basis of economic theory to posit a causal structure and then work out implications that can be checked against numerical data. Lenoir liked also to use the mathematical tools of the new British statistics, such as correlation, with which he largely supplanted the traditional attention of the empirical economist to squiggles on a graph. In contrast to the typical economic graph of data, arranged along an axis of time, the method of correlation bypassed history to get at causal structures whose validity (it was presumed) persisted over an entire epoch or even canceled out time.

Like much history of economic thought, this book focuses on a succession of individuals whose social and institutional locatedness is treated as of secondary interest. LeGall, however, scrutinizes carefully the problem situations addressed by these economic writers, with a full awareness of their historical specificity. He also takes a broad view that embraces the methods and assumptions of natural science as well as those of economics. While I do not think that econometric work can be explained in terms of a unified world view of science, or that “science” underwent somehow a mutation, with economics trailing along behind, LeGall delineates impressively the ways that econometric work reflected its authors’ beliefs about the proper character of science. By his account, the development of econometrics appears to have been closely entwined with that of statistical mathematics from Quetelet to English biometry, and with novel ways to understand and deal with complexity that arose with the new statistics.