While IP may not stimulate true innovation and creativity, Hayek suggests that copyright might stimulate something more pernicious: the intellectual class. In The Intellectuals and Socialism, he writes:

In the sense in which we are using the term, the intellectuals are in fact a fairly new phenomenon of history. Though nobody will regret that education has ceased to be a privilege of the propertied classes, the fact that the propertied classes are no longer the best educated and the fact that the large number of people who owe their position solely to the their general education do not possess that experience of the working of the economic system which the administration of property gives, are important for understanding the role of the intellectual. Professor Schumpeter, who has devoted an illuminating chapter of his Capitalism, Socialism, and Democracy to some aspects of our problem, has not unfairly stressed that it is the absence of direct responsibility for practical affairs and the consequent absence of first hand knowledge of them which distinguishes the typical intellectual from other people who also wield the power of the spoken and written word. It would lead too far, however, to examine here further the development of this class and the curious claim which has recently been advanced by one of its theorists that it was the only one whose views were not decidedly influenced by its own economic interests. One of the important points that would have to be examined in such a discussion would be how far the growth of this class has been artificially stimulated by the law of copyright.

Yet another strike against copyright!

Here is another one from Hayek on IP, written later and without any ambiguity:

""" Just to illustrate how great out ignorance of the optimum forms of delimitation of various rights remains - despite our confidence in the indispensability of the general institution of several property - a few remarks about one particuilar form of property may be made. [...]

The difference between these and other kinds of property rights is this: while ownership of material goods guides the user of scarce means to their most important uses, in the case of immaterial goods such as literary productions and technological inventions the ability to produce them is also limited, yet once they have come into existence, they can be indefinitely multiplied and can be made scarce only by law in order to create an inducement to produce such ideas. Yet it is not obvious that such forced scarcity is the most effective way to stimulate the human creative process. I doubt whether there exists a single great work of literature which we would not possess had the author been unable to obtain an exclusive copyright for it; it seems to me that the case for copyright must rest almost entirely on the circumstance that such exceedingly useful works as encyclopaedias, dictionaries, textbooks and other works of reference could not be produced if, once they existed, they could freely be reproduced.

Similarly, recurrent re-examinations of the problem have not demonstrated that the obtainability of patents of invention actually enhances the flow of new technical knowledge rather than leading to wasteful concentration of research on problems whose solution in the near future can be foreseen and where, in consequence of the law, anyone who hits upon a solution a moment before the next gains the right to its exclusive use for a prolonged period."""

The Fatal Conceit: The Errors of Socialism, 1988 (p. 35) Friedrich von Hayek

It seems to me that the case for copyright must rest almost entirely on the circumstance that such exceedingly useful works as encyclopaedias, dictionaries, textbooks and other works of reference could not be produced if, once they existed, they could freely be reproduced.

So much for the case for copyright, then. Such exceedingly useful works as Wikipedia, Wiktionary, and the various Wikibooks certainly have been and continue to be produced even though they can be freely reproduced.