engineering

Jules Dupuit

Jules Dupuit is a engineering topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Jules Dupuit rather than just read about it. In short: Arsène Jules Étienne Juvenal Dupuit (18 May 1804 – 5 September 1866) was a French civil engineer and economist. He was born in Fossano, Cisalpine Republic then under the rule of Napoleon Bonaparte.

Key takeaways

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Reference excerpt

Arsène Jules Étienne Juvenal Dupuit (18 May 1804 – 5 September 1866) was a French civil engineer and economist. He was born in Fossano, Cisalpine Republic then under the rule of Napoleon Bonaparte. At the age of ten he went to Versailles with his family where he studied — winning a Physics prize at graduation. He then studied in the École Polytechnique as a civil engineer. He gradually took on more responsibility in various regional posts. He received a Légion d'honneur in 1843 for his work on the French road system, and shortly after moved to Paris. He also studied flood management in 1848 and supervised the construction of the Paris sewer system. He died in Paris. Engineering questions led to his interest in economics, a subject in which he was self-taught. His 1844 article was concerned with deciding the optimum toll for a bridge. It was here that he introduced his curve of diminishing marginal utility. As the quantity of a good consumed rises, the marginal utility of the good declines for the user. So the lower the toll (lower marginal utility), the more people who would use the bridge (higher consumption). Conversely as the quantity rises (people allowed on the bridge), the willingness of a person to pay for that good (the price) declines. Thus, the concept of diminishing marginal utility should translate itself into a downward-sloping demand function. In this way he identified the demand curve as the marginal utility curve. This was the first time an economist had put forward a theory of demand derived from marginal utility. Although not the first time that the demand curve had been drawn, it was the first time that it had been proved rather than asserted. Dupuit, however, did not include a supply curve in his theory. Dupuit went on to define "relative utility" as the area under the demand/marginal utility curve above the price and used it as a measure of the welfare effects of different prices – concluding that public welfare is maximized when the price (or bridge toll) is zero. This was later known as Marshall's "consumer surplus". Dupuit's reputation as an economist does not rest on his advocacy of laissez-faire economics (he wrote "Commercial Freedom" in 1861) but on frequent contributions to periodicals. Wanting to evaluate the net economic benefit of public services, Dupuit analysed capacities for economic development, and attempted to construct a framework for utility theory and measuring the prosperity derived with public works. He also wrote on monopoly and price discrimination. Dupuit also considered the groundwater flow equation, which governs the flow of groundwater. He assumed that the equation could be simplified for analytical solutions by assuming that groundwater is hydrostatic and flows horizontally. This assumption is regularly used today, and is known by hydrogeologists as the Dupuit assumption.

Works "De la mesure de l'utilité des travaux publics". Annales des ponts et chaussées: Partie technique. Mémoires et documents. 8: 332–375. 1844 – via Google Books. "De l'influence des peages sur l'utilite des voies de communication". Annales des ponts et chaussées: Partie technique. Mémoires et documents. 17: 170–248. 1849 – via Google Books. "De l'utilité et de sa mesure: de l'utilité publique". Journal des économistes. 36: 1–27. 1853 – via Google Books. La liberté commerciale: son principe et ses conséquences. Paris: Guillaumin et ce. 1861 – via Google Books. "Du principe de propriété -- le juste -- l'utile". Journal des économistes. 29: 321 - 347. 1861 – via Google Books. De l'utilité et de sa mesure: Écrits choisies et republiés par Mario de Bernardi (PDF). Torino: La riforma sociale. 1934.

Notes

See also Robert Ekelund

References Blaug, Mark, ed. (1986). "Dupuit, Arsène Jules Étienne Juvenel". Who's Who in Economics: A Biographical Dictionary of Major Economists 1700-1986 (2nd ed.). Wheatsheaf Books Limited. p. 234-235. ISBN 978-0-7450-0230-9 – via Internet Archive. Hager, W.H. (2004): Jules Dupuit—Eminent Hydraulic Engineer. Journal of Hydraulic Engineering, Volume 130, Issue 9, pp. 843–848. doi:10.1061/(ASCE)0733-9429(2004)130:9(843) Dupuit, Arsène Jules Étienne Juvénal (1844): De la mesure de l’utilité des travaux publics, Annales des ponts et chaussées, Second series, 8. Translated by R.H. Barback as On the measurement of the utility of public works, International Economic Papers, 1952, 2, 83–110 reprinted in: Arrow, Kenneth; Skitovsky, Tibor, eds. (1969). Readings in welfare economics. Translated by R. H. Barback. Homewood, IL: Richard D. Irwin. pp. 255–283 – via Internet Archive. Edgeworth, Francis (1894). "DUPUIT, A. J. Etienne-Juvenal (1804-1866)". In Palgrave, R. H. Inglis (ed.). Dictionary of Political Economy. Vol. 1 (A-E). London: Macmillan and Co. pp. 654-655 – via Google Books. Einaudi, Luigi (1934). "Préface". Dupuit, Jules - De l'utilité et de sa mesure: Écrits choisies et republiés par Mario de Bernardi (PDF) (in French). Torino: La riforma sociale. pp. 11–18. Ekelund, Robert; Hébert, Robert F. (1999). Secret Origins of Modern Microeconomics: Dupuit and the Engineers. Chicago: University of Chicago Press – via Internet Archive. Hayek, Friedrich A. (1991). "Jules Dupuit". In Bartley III, W.W.; Kresge, Stephen (eds.). The Trend of Economic Thinking (The Collected Works of F. A. Hayek). Vol. 3. Chicago and London: The University of Chicago Press and Routledge. pp. 350- 352. ISBN 978-0-86597-742-6 – via Internet Archive. Jevons, William Stanley (1879). "Preface to the Second Edition". The Theory of Political Economy (2nd ed.). London: Macmillan and Co. pp. xxx-xxxi – via Internet Archive. Mahyer (1934). "Notice biographique". Dupuit, Jules, De l'utilité et de sa mesure: Écrits choisies et republiés par Mario de Bernardi (PDF) (in French). Torino: La riforma sociale. pp. 209–216.

External links Biography of Jules Dupuit "Arsène Jules Émile Juvénal Dupuit, 1804-1866". HET website. Retrieved 18 June 2024. Works by or about Jules Dupuit at the Internet Archive

Illustrations

Worked examples

Example 1 — a first encounter with Jules Dupuit

Start with the simplest possible case. Write down what Jules Dupuit claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In engineering, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Jules Dupuit before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Jules Dupuit ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Jules Dupuit

In research: Jules Dupuit appears in engineering research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Jules Dupuit in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Jules Dupuit is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1804 births, 1866 deaths, 19th-century French businesspeople, so understanding it makes those chapters shorter.
In everyday life: Look for Jules Dupuit outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Jules Dupuit in 20 minutes

Read the reference excerpt below once, without taking notes.
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Frequently asked questions

What is Jules Dupuit in simple terms?

Why does Jules Dupuit matter?

Because it connects several engineering ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Jules Dupuit?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Jules Dupuit.