Medary.com

From The Road To Serfdom, by F. A. Hayek, 1944, Fiftieth Anniversary Edition, 1994, The University of Chicago Press.

And because all the details of the changes constantly affecting the conditions of demand and supply of the different commodities can never be fully known, or quickly enough be collected and dissemenated, by any one center, what is required is some apparatus of registration which records all of the relevant effects of individual actions and whose indications are at the same time the resultant of, and the guide for, all of the individual decisions. This is precisely what the price system does under competition, and what no other system even promises to accomplish.

Excerpted under Fair Use for purposes of non-commercial education, discussion and comment. Any transcription or typographical errors are mine.