I was first alerted to this by Matt Zwolinski of Bleeding Heart Libertarians. It comes from Adam Smith, An Inquiry Into the Nature and Causes of the Wealth of Nations:
The property which every man has in his own labour, as it is the original foundation of all other property, so it is the most sacred and inviolable. The patrimony of a poor man lies in the strength and dexterity of his hands; and to hinder him from employing this strength and dexterity in what manner he thinks proper without injury to his neighbour, is a plain violation of this most sacred property. It is a manifest encroachment upon the just liberty both of the workman, and of those who might be disposed to employ him. As it hinders the one from working at what he thinks proper, so it hinders the others from employing whom they think proper. To judge whether he is fit to be employed, may surely be trusted to the discretion of the employers whose interest it so much concerns. The affected anxiety of the law–giver lest they should employ an improper person, is evidently as impertinent as it is oppressive.
This comes from the American Wood Council, which publishes the Wood Frame Construction Manual, a building code that my town is required to use:
To increase the use of wood by assuring the broad regulatory acceptance of wood products, developing design tools and guidelines for wood construction, and influencing the development of public policies affecting the use and manufacture of wood products.
There is a clear conflict of interest when an organization stands to gain financially by having its own standards adopted universally.
This comes from F. A. Hayek in Individualism and Economic Order:
Especially remarkable [...] is the explicit and complete exclusion from the theory of perfect competition of all personal relationships existing between the parties. In actual life the fact that our inadequate knowledge of the available commodities or services is made up for by our experience with the persons or firms supplying them– that competition is in large measure competition for reputation or good will– is one of the most important facts which enables us to solve our daily problems. The function of competition here is to teach us who will serve us well: which grocer or travel agency, which department store or hotel, which doctor or solicitor, we can expect to provide the most satisfactory solution for whatever particular personal problem we may have to face. Evidently in all these fields competition may be very intense, just because the services of the different persons or firms will never be exactly alike, and it will be owing to this competition that we are in a position to be served as well as we are.