The range of V_J spans a continuum from space to time. Space, the input by which economic activity acquires a physical extent in which to happen, does not perish as it is used. As long as the rent is paid, the same space can be used over and over again for, say, the assembly of products. Quite unlike the other factors of production, space always exists in one and the same extent. Its V_J is therefore zero.

Time, the obverse of space, is composed of moments that all perish immediately as they come into existence. Labor hours are indeed used-up in the assembly of products, along with the other factors of production; but they cannot be stored in inventory until they are needed. Any availability of labor that is not used is wasted. Its V_L is therefore infinite.

Since parameters that compute to zero or infinity have ways of making themselves unwelcome in mathematical analyses, SFEcon needs to commit a few acts of philosophy in order to avoid treating pure abstractions (time and space) as economic goods. Space, for example, becomes an economic good only by virtue of physical improvements and certain dispensations of ownership. And examinations of these highly tangible matters should reveal periodicities giving rise to useable values of its V_J.

The philosophy of time as an economic good is given its due on a separate page where SFEcon indentifies the household product as leisure time, and labor as the residual of leisure with the population's experience of time. Each economically competent individual continuously distributes the 8766 hours/year he experiences either as leisure or as labor in the various economic sectors. If we are to avoid using infinity as the V_L by which this distribution is controlled, what can be used in its stead?

An operative sense of V_J suggests that V_L should express the delay, or reluctance a worker might feel in changing his profession or place of employment; or the degree of resistance an economic sector experiences in realigning its labor force to changes in its technical environment. The considerations used to compose a V_L might, for example, depend on the amount of re-training it would take to equip oneself for a new profession. Here V_L can be used to separate a national population into social classes:

V_L would be quite high for the least-skilled of workers because many sectors use what they offer in the same way. A field hand in the agricultural sector can be transformed into a ditch-digger in the utilities sector, or enlisted in a clean-up crew for the construction sector, without much re-training.

V_L would, by contrast, be quite low for those with the skills required of professional classes. Thus the doctor who finds his field becoming crowded might well decide to simply finish his career amidst the diminishing opportunities of his profession, rather than re-invest in the time and training it would take to become a lawyer.