Surplus

The term surplus is used in economics for several related quantities. The consumer surplus is the amount that consumers benefit by being able to purchase a product for a price that is less than they would be willing to pay. The producer surplus is the amount that producers benefit by selling at a market price that is higher than they would be willing to sell for. Note that producer surplus flows through to the owners of the factors of production, unlike economic profit which is zero under perfect competition. If the markets for factors are perfectly competitive as well, producer surplus ultimately ends up as economic rent to the owners of scarce inputs such as land.