But a theory is not like an airline or bus timetable. We are not interested simply in the accuracy of its predictions. A theory also serves as a base… - Ronald Coase

Transaction costs were used in the one case to show that if they are not included in the analysis, the firm has no purpose, while in the other I showed, as I thought, that if transaction costs were not introduced into the analysis, for the range of problems considered, the law had no purpose.

The question always is, will it pay to bring an extra exchange transaction under the organizing authority? At the margin, the costs of organizing within the firm will be equal either to the costs of organizing in another firm or to the costs involved in leaving the transaction to be “organised” by the price mechanism. Business men will be constantly experimenting, controlling more or less, and in this way equilibrium will be maintained. This gives the position of equilibrium for static analysis.

I can't remember [of a good regulation]. Regulation of transport, regulation of agriculture—agriculture is a, zoning is z. You know, you go from a to z, they are all bad. There were so many studies, and the result was quite universal: The effects were bad.