In economics and related disciplines, a transaction cost is a cost incurred in making an economic exchange of some sort, or in other words the cost of participating in a market.
Transaction costs can be divided into three broad categories:
For example, the buyer of a used car faces a variety of different transaction costs. The search costs are the costs of finding a car and determining the car's condition. The bargaining costs are the costs of negotiating a price with the seller. The policing and enforcement costs are the costs of ensuring that the seller delivers the car in the promised condition.
The idea that transactions form the basis of an economic thinking was introduced by the institutional economist John R. Commons (1931). He said that:
These individual actions are really trans-actions instead of either individual behavior or the "exchange" of commodities. It is this shift from commodities and individuals to transactions and working rules of collective action that marks the transition from the classical and hedonic schools to the institutional schools of economic thinking. The shift is a change in the ultimate unit of economic investigation. The classic and hedonic economists, with their communistic and anarchistic offshoots, founded their theories on the relation of man to nature, but institutionalism is a relation of man to man. The smallest unit of the classic economists was a commodity produced by labor. The smallest unit of the hedonic economists was the same or similar commodity enjoyed by ultimate consumers. One was the objective side, the other the subjective side, of the same relation between the individual and the forces of nature. The outcome, in either case, was the materialistic metaphor of an automatic equilibrium, analogous to the waves of the ocean, but personified as "seeking their level." But the smallest unit of the institutional economists is a unit of activity – a transaction, with its participants. Transactions intervene between the labor of the classic economists and the pleasures of the hedonic economists, simply because it is society that controls access to the forces of nature, and transactions are, not the "exchange of commodities," but the alienation and acquisition, between individuals, of the rights of property and liberty created by society, which must therefore be negotiated between the parties concerned before labor can produce, or consumers can consume, or commodities be physically exchanged".
The term "transaction cost" is frequently thought to have been coined by Ronald Coase, who used it to develop a theoretical framework for predicting when certain economic tasks would be performed by firms, and when they would be performed on the market. However, the term is actually absent from his early work up to the 1970s. While he did not coin the specific term, Coase indeed discussed "costs of using the price mechanism" in his 1937 paper The Nature of the Firm, where he first discusses the concept of transaction costs, and refers to the "Costs of Market Transactions" in his seminal work, The Problem of Social Cost (1960). The term "Transaction Costs" itself can instead be traced back to the monetary economics literature of the 1950s, and does not appear to have been consciously 'coined' by any particular individual.