Quasi-rent refers to payments made on any factors of production that are temporarily fixed in supply. It is a concept used in economics to describe a situation where a factor of production (such as land, machinery, or even labor) becomes scarce and commands a higher price than would be the case if it were in abundant supply. In other words, quasi-rent represents the extra income earned by a factor of production that is not permanent, but is nevertheless being used to produce goods or services. This is because the supply of the factor is fixed in the short run, but can be adjusted in the long run.