In economics and related disciplines, a transaction cost is a cost in making any economic trade when participating in a market. The idea that transactions form the basis of economic thinking was introduced by the institutional economist John R. Commons in 1931, and Oliver E. Williamson's Transaction Cost Economics article, published in 2008, popularized the concept of transaction costs. Douglass C. North argues that institutions, understood as the set of rules in a society, are key in the determination of transaction costs. In this sense, institutions that facilitate low transaction costs, boost economic growth.
Williamson defines transaction costs as the costs of running an economic system of companies, and unlike production costs, decision-makers determine strategies of companies by measuring transaction costs and production costs. Transaction costs are the total costs of making a transaction, including the cost of planning, deciding, changing plans, resolving disputes, and after-sales. Therefore, the transaction cost is one of the most significant factors in business operation and management.
Douglass North states that there are four factors that comprise transaction costs – "measurement", "enforcement", "ideological attitudes and perceptions", and "the size of the market". Measurement refers to the calculation of the value of all aspects of the good or service involved in the transaction. Enforcement can be defined as the need for an unbiased third party to ensure that neither party involved in the transaction reneges on their part of the deal. These first two factors appear in the concept of ideological attitudes and perceptions, North's third aspect of transaction costs. Ideological attitudes and perceptions encapsulate each individual's set of values, which influences their interpretation of the world. The final aspect of transaction costs, according to North, is market size, which affects the partiality or impartiality of transactions. Dahlman (1979) categorized the content of transaction activities.