In economics, an implicit cost, also called an imputed cost, implied cost, or notional cost, is the opportunity cost equal to what a firm must give up in order to use factor of production which it already owns and thus does not pay rent for. It is the opposite of an explicit cost, which is borne directly. In other words, an implicit cost is any cost that results from using an asset instead of renting it out or selling it. The term also applies to foregone income from choosing not to work.