# Jules Dupuit

Date of Birth: 05/18/1804

Age: 62

Place of birth: Fossano

Citizenship: France

**Background**

Jules Dupuis was born May 18, 1804 th in Fossano, Italy (Fossano, Italy), during the reign of Napoleon Bonaparte (Napoleon Bonaparte). In ten years, he emigrated to France (France), together with his family, where he studied at Versailles (Versailles) - and won a prize in physics at the end. Continuing to receive education, Dupuis studied at the Ecole Polytechnique (Ecole Polytechnique) in the civil engineer.

Pursuing the construction and design of railways, Jules gradually took on more responsibilities. For his work in the French road system in 1843, he received the Legion of Honor (L & # 233; gion d`honneur) and shortly thereafter moved to Paris (Paris). He was also involved in issues related to navodneniemv Paris in 1848, and supervised the construction of the Paris sewer system.

He died on September 5, 1866 th, in Paris.

Engineering Dupuis led to economic interest. In this area, he was self-taught. His article `On the measure of the usefulness of civil sooruzheniy` of 1884 was devoted to finding ways of solving the optimal crossing the bridge. As one of the marginalist predecessors Dupuis presented in the article curve of diminishing marginal utility, showing failure to apply the method of determining the efficacy (usefulness) of economic activities. He denied the statement about the usefulness of civil engineering structures, including bridges and roads, on the amount of cash flows from operating them. According to him, the more people will use the bridge (higher consumption), the lower the person`s willingness to pay a good price.

In essence, Dupuis first analyzed the consumer surplus. It was the first time that an economist has put forward the theory of demand, starting from the theory of marginal utility. Although the demand curve was derived to him, it was just a statement, while Dupuis gave proof through the derivative of the curve of marginal utility. However, in his theory, he did not include the supply curve.

As an economist, Dupuis has earned a reputation not only on his work `Commercial svoboda` (` Commercial Freedom`)-th 1861, declare the government non-interference in the affairs of individuals, vbiznes and trade, but on his abundant contributions to periodicals. Dupuis reviewed the potential for economic development, wanting to evaluate the net economic benefit of public services, and tried to build a foundation for the theory of utility and the measurement of well-being derived from public works. He also wrote about the monopoly and price discrimination.

Among other things, Jules Dupuis reflected on the groundwater flow equation, putting forward the assumption of constancy of the heads vertically. He suggested that the equation can be simplified to create complete analytical solutions, taking groundwater and hydrostatic flows horizontally. This assumption is widely used to this day in hydrology.