6. _The rate of contract interest on safe long-time loans registers pretty nearly the prevailing rate of time-discount in the community._ There are of course different capital markets, and the estimates put upon next year's income as compared with this year's is very different in Montana, New York, and London. Because of the friction in the transfer of investments from one locality to another, these differences may persist indefinitely; but within each capital market the interest on any particular loan must, for reasons readily seen, tend to conform pretty closely to the prevailing rate. Various groups of men living in the same community have, however, varying estimates of time-value. The increase of safe long-time bonds issued by strong corporations and by wealthy nations as, for example, the New York Central Railroad, and the government of Great Britain, gives a large number of choice investments where the element of risk is almost entirely absent. Various agencies have developed for making the loans, that is, for bringing the borrower and lender together with the minimum of trouble and expense. Other efficient, but somewhat more costly, agencies for bringing together the owners of loanable capital and men wishing to use capital are savings-banks, building and loan associations, insurance companies issuing endowment policies, and mortgage-investment companies of many kinds. While on the one side of the bidding are thousands of lenders offering to exchange ready money for assured incomes, on the other are thousand of borrowers offering to exchange the promise of assured incomes for ready money. If either of these classes got far out of touch with the prevailing rate of capitalization, to which all the valuations are adjusted, that class would lose greatly. [Sidenote: Relations between the concepts of rent, interest, and time-value] 7. _All the net usufructs actually yielded by wealth are rents; economic time-discount is never a realized income; it is merely a calculation form, or anticipation of the difference between present and future gratifications._ There has been much discussion as to what should be the relations in thought between rent and interest. Space permits here only an indication of the view on this question involved in the foregoing treatment. Rent, as the term is here applied, includes all the net productivity attributable to the ownership and use of capital, whether the yield be in economic form (in an increment of value) or in contractual form. Even contract money-interest must be looked upon as a species of the genus contract rent, the peculiarity in the money loan being merely that the thing which it is agreed to return is a certain number of units of the standard money.