Human mental and physical capacities to work have elastic but definite natural limits. Those capacities must be continuously restored and enhanced through nourishment, rest and social interaction. Over the longer term that capacity for labour also has to be replenished by a new generation of youth, reared by the previous generation.
It is this combination of definite limits and of the need for continuous recuperation and replacement that, according to Paul Burkett, gives labour-power the characteristics of a common-pool resource. As Burkett explained, Karl Marx also regarded labour power not merely as a marketable asset of private individuals but as a "reserve fund for the regeneration of the vital force of nations." "From the standpoint of the reproduction and development of society," Burkett elaborated, "labor power is a common-pool resource – one with definite (albeit elastic) natural limits."
Here is where I would amend Burkett's definition to designate disposable time -- rather than labour power -- as the common-pool resource. The rationale for doing so is that the working day consists of two distinct parts, one of which is the labour time necessary to provide for the subsistence of the worker and the worker's family and represented by the wage. The second part of the working day is labour performed to create value that is taken by capital and is referred to as surplus labour time or surplus value. The proportion of surplus labour time to necessary labour time, however, is not a constant and changes with changes in the length of the working day and the productivity of labour.