From F.A. Hayek’s Competition as a Discovery Procedure:

I should like to begin with the observation that market theory often prevents access to a true understanding of competition by proceeding from the assumption of a “given” quantity of scarce goods. Which goods are scarce, however, or which things are goods, or how scarce or valuable they are, is precisely one of the conditions that competition should discover: in each case it is the preliminary outcomes of the market process that inform individuals where it is worthwhile to search.