"Farm" comes from the mediaeval Latin firma, meaning "a fixed agreement, contract".
Tax farming was originally a Roman practice whereby the burden of tax collection was reassigned by the Roman State to private individuals or groups. It provided a method for collecting taxes across a large area without the need for a tax-collecting bureaucracy. In essence, these individuals or groups paid the taxes for a certain area (and for a certain period of time) and then attempted to cover their outlay by collecting money or saleable goods from the people within that area. The system was set up by Gaius Gracchus in 123 BC primarily to increase the efficiency of tax collection within Rome itself but the system quickly spread to the Provinces. Within the Roman Empire, these private individuals and groups which collected taxes in lieu of the bid (i.e. rent) they had paid to the state were known as publicani, of whom the best known is the disciple Matthew, a publicanus in the village of Capernaum in the province of Galilee.
In Greek, Tax collectors were known as "Telones".
"Telones" comes from "Telos" - an end result (completeness), a levy, a contract, and "Onos" is the "price" agreed to buy the contract.
Wikipedia extract. The "Telones" profit becomes the excess of whatever revenues he can extract from the farm less the rents payable, less his administration, levying and collection expenses. The skill of the tenant of a farm is therefore firstly in negotiating a favourable rent which he does by overstating the riskiness (variability) of the cash flow stream in question and secondly in his management of the debts thus assigned to him, that is to say his skills as a debt-collector and manager in general. He must also be satisfied that he has the ability to enforce payment of the debts, ultimately by use of a court of law, in which he must pay the standard fee for bringing a suit, under the legal system generally instituted by the government authority which is the lessor of the farm. He does not act as the lessor's agent but as a principal.
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