Substitution and Schumpeterian Effects Over the Lifecycle of Copyrighted Works

I have posted a new paper on SSRN.  The paper, titled Substitution and Schumpeterian Effects Over the Lifecycle of Copyrighted Works, develops the following two key insights. First, copyrighted works are affected by two types of competitive forces: substitutive competition and Schumpeterian competition. Second, the relevant magnitude of each of these competitive forces changes at various points over the lifecycle of copyrighted works. The earlier stages of a work's lifecycle are dominated by substitution effects, whereby many other works can function as very close substitutes. As the work develops to a full product, to which many other inputs have been added, it becomes less easily substitutable. This process intensifies as network effects of various kinds secure successful works' market position and render them less vulnerable to competition from close imitations. The competitive threat to which such works may be exposed becomes more Schumpeterian in nature: competition from other works which offer something new, and potentially preferable. Generally, copyright law unequivocally discourages merely substitutive competition, but is much less interested in discouraging Schumpeterian competition. This paper's time-based analysis provides both a justification to this distinction, as well as grounds to evaluating various existing rules and doctrines. It suggests that broader copyright protection (perhaps broader than the current) may be desirable at the early stages of works' lifecycle, whereas narrower protection (perhaps narrower than the current) may be justified as later stages.
The paper is freely available here; comments are welcome.