Alfred Marshall analysed the "quasi" version, while the traditional use of this term refers to the special case of a specific factor of production which is always present in a fixed quantity and therefore has zero supply cost.  
Formally, this economics term is defined as the difference between the total return from a factor of production and its supply price; that is, the minimum amount necessary to attain a factor of production.  Alfred Marshall analysed the "quasi" version, while the traditional use of this term refers to the special case of a specific factor of production which is always present in a fixed quantity and therefore has zero supply cost.  FTP, identify this term, most commonly used to refer to the price paid for use of land.
Formally, this economics term is defined as the difference between the total return from a factor of production and its supply price; that is, the minimum amount necessary to attain a factor of production.  
economic rent