Economic Surplus

In mainstream economics, economic surplus (also known as total welfare or Marshallian surplus after Alfred Marshall) refers to two related quantities. Consumer surplus or consumers' surplus is the monetary gain obtained by consumers because they are able to purchase a product for a price that is less than the highest price that they would be willing to pay. Producer surplus or producers' surplus is the amount that producers benefit by selling at a market price that is higher than the least that they would be willing to sell for.

In some schools of heterodox economics, the economic surplus denotes the total income which the ruling class derives from its ownership of scarce factors of production, which is either reinvested or spent on consumption.

In Marxian economics, the term surplus may also refer to surplus value, surplus product and surplus labour.