Willingness to accept in the context of "Consumer surplus"

In mainstream economics, economic surplus, also known as total welfare or total social welfare or Marshallian surplus (after Alfred Marshall), is either of 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; this is roughly equal to profit (since producers are not normally willing to sell at a loss and are normally indifferent to selling at a break-even price).

The sum of consumer and producer surplus is sometimes known as social surplus or total surplus; a decrease in that total from inefficiencies is called deadweight loss.

In economics, a reservation (or reserve) price is a limit on the price of a good or a service. On the demand side, it is the highest price that a buyer is willing to pay; on the supply side, it is the lowest price a seller is willing to accept for a good or service.

Reservation prices are commonly used in auctions, but the concept can be extended beyond. A party's best alternative to a negotiated agreement (BATNA), is closely related to their reservation price. Once a party determines their BATNA, they can further calculate their reservation price. In negotiations surrounding the price of a particular good or service, the reservation price is a singular number. However, this is not the only situation where reservation prices are seen. When multiple issues are being discussed, such as the size of salary and amount of benefits when applying for a new job position, the reservation price would be represented as a package, where multiple requirements need to be met.