Although the old conception of the Margin of Production--“margin of cultivation,” as it was called--as bounding an open space of free agricultural land be obsolete, the principle of the Margin remains, namely, that the better the opportunity to profit by use of any location on our earth over use of the most profitable location thereon to be had for nothing, the higher will the Rent of the former be. That marginal principle will persist so long as some locations are preferable to others. And in those circumstances Rent will continue and be allocated with reference to “marginal” or zero-value Land. The better the opportunity to profit by the use of any location above the most desirable to be had for nothing, the higher will be the Rent of the former. Whether the surplus of Production or possible Production be called Rent for Land, or deductions from Wages for superior opportunities to Labor, or be otherwise distinguished from Wages for Labor, it none the less exists as a distinct and natural allocation of Wealth produced from and upon Land by Labor. Although Rent depends wholly upon Labor for its Production it is a differential gain in Wealth which is due not to superior productiveness of Labor but to relative superiority of different kinds and locations of Land. This continuous allocation to Rent of shares of Labor-produced Wealth may--it constantly does--take on Capitalized forms. As Wealth is produced it flows toward the productive factors in two distinct and continuous streams--Wages for Labor and Rent for Land. But as Land has in business custom the rank of a commodity, the legal right of its owners to appropriate Rent assumes the form of Capitalized Land Value. An annual income from Rent, for example, be that income actual or only potential, may be bought and sold in business intercourse for a Capital sum or “purchase money.” Commonly it is so sold along with the legal Land title by which it is secured to the owner, but often with Artificial improvements, the whole being called “real estate,” as if the improvements and the Land were fundamentally identical. As a result, the word “rent” takes on in the customary business sense a different meaning from the meaning of Rent in the normal Economic sense. In private business it may mean annual “groundrent,” or annual house-and-ground “rent”; and when capitalized, all legal rental rights may be combined in Price or Value. A concurrent custom is the transformation noted above of Rent for Land into Capital value or selling Price.