# Consumer Surplus

• This is the difference between the price a consumer is willing to pay and the price he actually pays.
• For example if you were willing to buy a computer game for £50, but can buy it for £15 in the sales your consumer surplus is £35

#### Diagram Consumer and Producer Surplus

• Consumer Surplus is therefore the difference between the demand curve and the market price.
• We can also explain consumer surplus by using marginal utility. This is the utility you gain from consuming an extra unit of a good. If the Marginal utility is greater than the price, the difference is your consumer surplus.
• The demand curve is derived from our marginal utility. (see: marginal utility theory)
• #### A Person’s Consumer Surplus from Petrol

In the above diagram, at Q 500 litres, the MU is 80p > than the price = 50p.

### Producer Surplus

• This is the difference between the price a firm receives and the price it would be willing to sell it at.
• Therefore it is the difference between the supply curve and the market price