Regularities concerning how entry, exit, market structure, and innovation vary from the birth of technologically progressive industries through maturity are summarized. A model emphasizing differences in firm innovative capabilities and the importance of firm size in appropriating the returns...

Using firm data disaggregated by industry, the authors establish a set of regularities in the distribution of firm R&D intensities within manufacturing industries. The authors show how a simple probabilistic process, in which change influences a key unobserved determinant of R&D and firm size...