"Michael Emmett Brady argues that Hayek’s concept of uncertainty and the role of knowledge are quite distinct from that of fundamental uncertainty as defined by Frank Knight and Keynes:
“Uncertainty for Hayek means that each individual decision maker only has a small piece of the puzzle. However, as a whole, the aggregated set of all decision makers have a complete set of all relevant knowledge. There are no pieces missing, lacking or unavailable from the puzzle. Market prices organize and synthesize the aggregate amount of knowledge so that market price signals, understood only by savvy, knowledgeable entrepreneurs, [eliminate] … any uncertainty.” (p. 14)Brady charges that the “Austrian use of the term ... uncertainty actually means dispersed knowledge” (p. 16), which bears further investigation."
“Keynes, Knight and Schumpeter deny Hayek’s claim that the market generates price vectors which concentrate the knowledge so that savvy, knowledgeable entrepreneurs can act on this information and solve the problem of uncertainty. Uncertainty means vital important information is missing. Pieces from the puzzle are missing and will not turn up in the future” (p. 14).
“Hayek could not accept the standard concept of uncertainty as defined by Keynes, Knight and Schumpeter because it would then be impossible for market prices to concentrate knowledge that did not exist. In conclusion, nowhere in any of Hayek’s three articles on Knowledge in Economics in 1937, 1945 and 1947 does Hayek deal with the standard view that uncertainty means knowledge that is not there.” (p. 15).