Madsen, Jakob Brøchner; Saxena, Shishir; Ang, James B. - 2009
study is, to the best of our knowledge, the first attempt to test the importance of R&D
for growth and the validity of … zero if all innovations are replication of existing
knowledge and 1 if none of the new innovations are replications, φ is … returns to scale in knowledge
production, and β is the coefficient of product proliferation. The key distinction endogenous …