This paper evaluates the sources of transitory market power in the market for personal computers (PCs) during the late 1980's. Our analysis is motivated by the coexistence of low entry barriers into the PC industry and high rates of innovative investment by a small number of PC manufacturers. We...

We evaluate the sources of transitory market power in personal computers in the late 1980s to explain how high rates of imitative entry coexisted with high rates of innovative investment. We measure the impact of different principles of differentiation (PDs); each PD reflects a distinct notion...

This paper evaluates the sources of transitory market power in the market for personal computers (PCs) during the late 1980's. Our analysis is motivated by the coexistence of low entry barriers into the PC industry and high rates of innovative investment by a small number of PC manufacturers. We...

Whole eras of technical progress and economic growth appear to be driven by a few key technologies, which we call General Purpose Technologies (GPT's). Thus the steam engine and the electric motor may have played such a role in the past, whereas semiconductors and computers may be doing as much...