# What does the area defined by two different values for quantity under a supply curve represent?

Assume that a and b (b is greater than a) indicate the quantity of supply on a linearly increasing supply curve. How can be the area formed by those two points under the supply curve interpreted? The interpretation should be made independent of a demand curve. That means no equilibrium price and producer surplus to account for. Could that be the difference between production costs for the given range of quantity?

• Why do you tag it as producer surplus while writing there is no producer surplus to account for? – Giskard Feb 6 '17 at 11:33
• Because the calculation of the questioned region is mathematically similar to the calculation of producer surplus. The expertise for the calculation of the producer surplus can assist for the corresponding interpretation. – Dirk Feb 6 '17 at 11:39
• It cannot: no price is given. The only similarity is that both are areas. – Giskard Feb 6 '17 at 11:41
• I don't think so. – Dirk Feb 6 '17 at 11:47

To get the area you integrate. That is, you get back the variable cost. So the area below the supply curve between $a$ and $b$ is the difference of the variable costs.