Surplus labour (German:
Mehrarbeit) is a concept used by
Karl Marx in his critique of
political economy. It means labour performed in excess of the labour necessary to produce the means of livelihood of the worker ("necessary labour"). The "surplus" in this context means the
additional labour a worker has to do in his/her job, beyond earning his own keep. According to
Marxian economics, surplus labour is usually uncompensated (unpaid) labour. Marxian economics regards surplus labour as the ultimate source of capitalist
profits.