The value of land in the final analysis is the amount of its economic or ground rent capitalized. In the case of farm land its fertility and accessibility determine its rent. Urban land must usually be improved with buildings in order to produce rent, but even if unimproved it has a potential rent which would be made actual if a suitable improvement were made upon it. The amount of ground rent of a parcel of urban land is the total amount of the gross rent derived from the land and building less actual expenses, charges and taxes, and after deducting interest on the cost of the building and a sufficient amount for depreciation of the building. The net amount after such deductions would represent the amount paid for the use of the land or the location, that is to say, it is the economic or ground rent. The value is obtained by considering the ground rent to be the income on the sum at a fixed percentage. The percentage used should be the prevailing average rate of interest on investments. However, the same interest rate cannot be used in connection with property of all classes. Some property, such as that used for financial or business purposes, is of a very high type and its value is stable or increasing, and the rate of return on it would be low compared with that from other property in the same manner as the return on high-class bonds and other securities is relatively low. Other property, such as that used for cheap tenements, may be considered to have reached its maximum value and may be adversely affected by changing conditions. The rate of return on property of the latter class should be higher as having an element of greater risk for the investor. In any case to obtain the maximum ground rent the building should be the suitable improvement for the location and should be managed in such a way as to obtain the best income possible.