Transaction cost analysis is an extremely important idea in economics, roughly since Coase's The Theory of The Firm, in late 30s. The basic idea is that, contarry to neoclassical orthodoxy, every transaction is costly, and this cost must be born by someone. You cannot assume that, for example, an agreement of trade my ;abor for your money is like trading an apple for a dime (John Roemer's statement of the assumption). Rather, creating and navigating a labor market is costly for both sides,a nd enforcing a labor contract is a whole another story. In fact, tarding apples for dimes is pretty tricky too.
The dean of TCA is Oliver Williamson. See his great book The Economic Institutions of Capitalism. There is a huge literature on the Coase Theorem, so called, it's not a real theorem, and it's unclear exactly what it is, but Coase used, and maybe invented, the idea of TCA to expalin why some events occur in a nonmarket way insidea firm and other between firms in a market.
Joseph Stiglitz and George Akerloff, both recent Nobel winners, have made a lot of hay with TCA. Finally, although they did not describe it inm these terms, the fundamental insight of the Austrians (Hayek, Mises), that information is constly to acquire, is clearly linked to TCA.
So, this is not a notion to ignore, although it is complex and less than clear.
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