Q."Wages as a sum of money are paid under contract by an employer to a worker for services rendered" - Who said this ?

The definition of wages as money paid under contract for services is by Benham.

In distribution analysis, the reward for labour is the wage. Benham defined wages as "a sum of money paid under contract by an employer to a worker for services rendered." This is the money (nominal) wage concept — payment expressed in terms of money for work done. Walker, J. …