Name: consumer surplus from demand and integration
Uploaded: 2026-01-12T12:24:50.000Z
Duration: 1 min 29 s
Channel: JoVE

Un consommateur s’attend à payer un certain montant pour un produit. Si elle est vendue à un prix moindre, la différence entre ce que le consommateur était prêt à payer et ce qu’il a réellement payé est appelée le surplus du consommateur pour les individus.Calculer le bénéfice pour tous les consommateurs nécessite la courbe de demande, un graphique montrant le prix maximal que les consommateurs sont prêts à payer pour une quantité donnée d’un produit.Supposons qu’une quantité de produit x_c soit vendue à un prix de marché constant p_c. Ces valeurs fixent les limites nécessaires pour visualiser le surplus.La ligne horizontale indique le prix réel. L’écart vertical entre la courbe et cette ligne montre les économies par unité. La zone délimitée entre la courbe et la ligne de prix correspond à l’excédent total des consommateurs.Pour estimer cet excédent, l’intervalle de 0 à x_c est divisé en segments plus petits.En multipliant la différence de prix par la largeur du segment, on obtient un surplus partiel. En additionnant ces surplus partiels, on obtient une approximation appelée somme de Riemann.À mesure que les segments deviennent plus petits, cette somme tend vers l’intégrale définie qui donne le surplus total exact du consommateur.Ainsi, l’intégrale définie calcule précisément l’excédent total du consommateur — le bénéfice global pour le consommateur.

applications de l’intégration pour déterminer le surplus du consommateur

Applications of Integration to Find Consumer Surplus

En micro&#xE9;conomie, le surplus du consommateur repr&#xE9;sente le gain &#xE9;conomique que les consommateurs retirent de l&#x2019;achat d&#x2019;un bien ou d&#x2019;un service &#xE0; un prix inf&#xE9;rieur au prix maximal qu&#x2019;ils sont pr&#xEA;ts &#xE0; payer. Ce surplus provient des caract&#xE9;ristiques de la fonction de demande, qui relie la quantit&#xE9; d&#x2019;un bien au prix que les consommateurs sont pr&#xEA;ts &#xE0; payer. &#xC0; mesure que la quantit&#xE9; d&#x2019;un bien augmente, le prix que les consommateurs sont pr&#xEA;ts &#xE0; payer pour chaque unit&#xE9; suppl&#xE9;mentaire diminue g&#xE9;n&#xE9;ralement, ce qui conduit &#xE0; une courbe de demande d&#xE9;croissante.
Comprendre le surplus du consommateur
Lorsqu&#x2019;un produit est vendu &#xE0; un prix fixe, certains consommateurs auraient &#xE9;t&#xE9; pr&#xEA;ts &#xE0; payer plus que ce prix pour les premi&#xE8;res unit&#xE9;s. La diff&#xE9;rence entre ce que ces consommateurs &#xE9;taient pr&#xEA;ts &#xE0; payer et ce qu&#x2019;ils ont effectivement pay&#xE9; constitue une &#xE9;conomie individuelle. Ces &#xE9;conomies, lorsqu&#x2019;elles sont agr&#xE9;g&#xE9;es pour l&#x2019;ensemble des acheteurs, forment le surplus total du consommateur. Cette mesure refl&#xE8;te le b&#xE9;n&#xE9;fice global que les consommateurs retirent du fait de pouvoir acheter des biens &#xE0; un prix inf&#xE9;rieur &#xE0; leur prix maximal de volont&#xE9; de payer.
Approximation du surplus
Pour estimer le surplus total du consommateur, on peut diviser la quantit&#xE9; totale vendue en segments plus petits. Pour chaque segment, on calcule la diff&#xE9;rence entre la valeur donn&#xE9;e par la fonction de demande et le prix de vente effectivement pratiqu&#xE9;. Cette diff&#xE9;rence, multipli&#xE9;e par le nombre d&#x2019;unit&#xE9;s de ce segment, donne un surplus partiel. La somme des surplus partiels de tous les segments fournit une valeur approximative du surplus total du consommateur.
&#xC0; mesure que les segments deviennent de plus en plus petits, cette somme s&#x2019;approche d&#x2019;un calcul continu, convergeant finalement vers une int&#xE9;grale d&#xE9;finie qui repr&#xE9;sente pr&#xE9;cis&#xE9;ment le surplus total des consommateurs sur l&#x2019;ensemble de l&#x2019;intervalle de consommation. Cette approche permet aux &#xE9;conomistes de quantifier le b&#xE9;n&#xE9;fice des consommateurs &#xE0; l&#x2019;aide de m&#xE9;thodes fond&#xE9;es sur le calcul int&#xE9;gral, fond&#xE9;es sur le comportement observ&#xE9; de la demande.

Applications de l’intégration pour déterminer le surplus du consommateur

En micro&#xE9;conomie, le surplus du consommateur repr&#xE9;sente le gain &#xE9;conomique que les consommateurs retirent de l&#x2019;achat d&#x2019;un ...

applications-of-integration-to-find-consumer-surplus

Education

Enseignement

JoVE Core

Calculus

Calcul

Unit

Unité

Application of Techniques of Integration

Application des techniques d'intégration

KEY TERMS AND CONCEPTS

TERMES ET CONCEPTS CLÉS

consumer surplus from demand and integration

Consumer surplus measures the economic gain buyers receive when they pay less than the highest price they are willing to pay. In microeconomics, this idea comes from the demand function, which links quantity to the price consumers will pay. Because willingness to pay usually falls as quantity rises, the demand curve slopes downward.

When a product is sold at a fixed price, some buyers would have paid more for the first units they bought. The difference between that willingness to pay and the market price is an individual saving. When those savings are added for all buyers, they form the total consumer surplus.

Economists can estimate this surplus by splitting the total quantity sold into small parts. For each part, they subtract the actual selling price from the value given by the demand function. They then multiply that difference by the number of units in the part to get a partial surplus.

Adding all of the partial surpluses gives an approximation of the total consumer surplus. As the parts become smaller, the estimate becomes more exact. In the limit, the sum turns into a definite integral, which gives the total consumer surplus across the full range of consumption.

Consumer Surplus from Demand and Integration

consumer-surplus-from-demand-and-integration

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applications of integration to find consumer surplus

Consumer surplus measures the economic gain buyers receive when they pay less than the highest price they are willing to pay. In microeconomics, this idea comes from the demand function, which links quantity to the price consumers will pay. Because willingness to pay usually falls as quantity rises, the demand curve slopes downward. When a product is sold at a fixed price, some buyers would have paid more for the first units they bought. The difference between that willingness to pay and the...

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key terms and concepts

Learn how demand curves, willingness to pay, and definite integrals are used to estimate total consumer surplus in microeconomics.

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calculus

Consumer Surplus from Demand and Integration

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