Differentiating the Sale Price from Production Cost
When you see a determined supply curve, you need to understand that it comes from a determined technology of production used by the provider. Given that each possible technology creates its own relation between product and costs levels, some technologies give place to very steep supply slopes, while there are others that cause more horizontal curves of supply.
Independent from the slope of the curve or its exact position, the fact that the prices increase when the production increases means that a higher price has to be offered each time if the provider wants to obtain more units. This is the basic reason why prices move along the curves of supply.
Movements along the Supply Curve
The variation of the price of an item moves you along a determined curve of supply because the curve of supply represents the minimum pay you have to give the provider to that he or she offers the amount of the product you want.
Given that the structure of costs of a provider determines the position of the supply curve and the slope in it, changes in the structure of cost cause changes in the supply curve.
The important thing to remember is that any factor that changes the structures of cost of the producers moves their supply curves. The factors that make production be more expensive move the supply curves upwards, while the factors that reduce the costs move them downwards. Remember also that it is absolutely correct to consider that the supply curves move from right to left when the price structure changes.
