1. _Economic rent (likewise called natural, competitive, and sometimes rack rent) is to be distinguished from contract rent._ Economic rent is the market value of the usufruct, and contract rent is the amount a man pays for the use of wealth by virtue of an existing agreement. The one is impersonal or economic; the other is personal or legal, being fixed by agreements between persons. The rents usually spoken of are contract rents. The two diverge more or less. If the contract has been lately made the two will be nearly the same. Contracts of long standing often bind the tenant or borrower to pay either more or less than the present competitive price. If, after a time, the value of the use is greater than the contract rent, the tenant is fortunate in having his lease. But he is the loser if he is bound by lease or agreement to pay rent in a locality where land has become less valuable. Economic and contract rent usually diverge also because of the agreement that the owner, or lender, keep up the repairs and pay the taxes. Here it is simply the difference between gross and net rent. Custom may prevent the owner from charging all the usufruct of the agent is worth. If the contract rent is less than the economic rent, evidently the borrower enjoys a part of the usufruct, without charge, and to that degree is in the position of an owner. The usufruct in this case is divided between the two parties. Such instances were numerous in the Middle Ages in the renting of land, and still are found in many countries. Contract rent is based on economic rent and tends to conform to it whenever there is competition. The existence of economic rent is the basis of the agreement to pay contract rent. Prospective hirers of agents forecast what the use will be worth to them and make their bids accordingly. [Sidenote: The renting contract for the use of wealth] 2. _The renting contract is the agreement of a borrower to pay for the use of a thing and, at the end of the time, to restore it in good condition or pay for its complete repair._ In practical business it is necessary to have definite agreements to prevent disputes. Some provide that one party, some that the other party, shall keep up repairs. The form of the renting contract is observed by men in estimating the uses of their own wealth where no contract exists. If they count the gross product of an agent as rent, it is bad bookkeeping. In many cases it is necessary, therefore, to follow the form of the renting contract in order to determine the net yield of indirect goods. [Sidenote: The renting contract in the middle Ages]