Navier’s 1832 Contributions to the Finance, Governance, and Evaluation of Public Works

In 1832, the French journal Annales des Ponts et Chaussées published a paper by the engineer Claude-Louis Navier entitled “On the Execution of Public Works, Particularly Concessions” (Navier 1832). Although known to most engineers for his mathematical foundations of fluid mechanics, Navier was active more broadly in forming today’s fields of transportation engineering, structural engineering, engineering mechanics, engineering finance and management, and economics, as well as fluid mechanics (Cannone and Friedlander 2003).

In the late 1700s and early 1800s, French engineering led the systematic development and application of mathematics and early enlightenment thinking to a wide range of practical and societal problems (Langins 2004; Hayek 1952). The successes of this organized rational and mechanistic approach to understanding and solving problems has led to the intellectual and practical success of engineering and the incorporation of these ideas in economics, business, and industry. In this historical development, many engineers of the early and mid-1800s, particularly from the French École des Ponts et Chaussées and École Polytechnique, made contributions that became fundamental within and outside of engineering.

The contributions of this paper by Navier to economics and public policy were noted by Ekelund and Hébert (1999, pp. 74–77). These contributions are in two categories: (1) early phrasing of the fundamental principle of benefit–cost analysis, and (2) identification and discussion of the means of financing and organizing public works.

The benefit–cost principle is best known today from the US Flood Control Act of 1936 as “the benefits to whomsoever they may accrue are in excess of the estimated costs.” This common-sense principle has been applied at least since 1708, when it was applied by Abbé de Saint-Pierre (Jiang and Marggraf 2021). Navier’s paper formally states this as, “It is easy to see that, for this operation to not be onerous for taxpayers, the annual saving on transportation must at least equal the interest on capital expended, plus maintenance costs.” (Navier 1832, p. 16)

Such an idea appears to have been common among French engineers of that time, such as Courtois in 1833 (Theocharis 1988). Navier’s student, the famous Jules Dupuit, further developed this concept into the theory of consumers’ surplus in 1844 (Dupuit 1844), which became the foundation of modern microeconomics (Ekelund and Hébert 1973, 1999) and is seen as a foundation of modern benefit–cost analysis (Maneschi 1996).

In terms of financing and organizing public works, Navier identified four “means to execute public works” (Navier 1832, p. 4):

“We can distinguish the execution of public works mainly by the following financial means:

These fundamental approaches to public works finance and organization introduced in Navier’s paper remain relevant today. He then goes on to discuss the advantages and disadvantages of each approach with considerable insight.

Navier summarized this work as follows:

Today, many of these conclusions and insights are fundamental to the finance and management of civil engineering and public works.

Navier’s French engineering tradition, of which modern American engineering education is a direct descendant, began in the 1700s as an instrument for the centralization of state power (beginning with Louis IV, and continuing to Napoleon in the 19th century) (Langins 2004). As early French engineers addressed initial practical military, transportation, and structural problems, they saw a need to expand engineering’s formal mechanics approach to economic, finance, and ultimately social problems to achieve efficiencies and broader societal objectives. Today’s theories of capitalist economics and socialism both have roots in the work of Navier and his colleagues (Ekelund and Hébert 1999; Hayek 1952).

In our current age of specialization, Navier’s career and contributions remind us that serious generalists also are needed, who can put entire projects together in a larger social and economic context and can develop specialties that contribute well within the larger problem-solving context. Indeed, the general approach of engineering developed by Navier and many others in this era has proven itself to be as valuable for solving broad societal and technical problems as for solving the narrower problems of specialists. In this, effective generalists must be unafraid of specialist details, and also can contribute to specialist details and fundamentals. Navier’s overall interest and diverse engineering contributions were to create infrastructure that functions reliably and economically for the society as a whole. Although the importance of Navier’s well-known fundamental formalization of fluid dynamics is clear for the wide range of hydraulic structures and operations, these engineering accomplishments and others also reflect Navier’s fundamental insights into the governance and finance of public works.

A full translation of the original paper in French is included in the Supplemental Materials to this essay. The English translation should make this work more available to engineers, economists, and scholars of infrastructure economics and policy; to hydraulic engineers interested in the broader contributions of founders of fluid mechanics; and to engineers and engineering students generally to show how many great engineers contribute as serious generalists. This translation is for contemporary engineering and public policy readers. Therefore, when several ways of translating were available, English wording was chosen to make the meaning more readable and understandable for modern professionals and students. (This process made me sympathetic to the difficulties of creating useful translations.)