ENTRY INTO PHARMACEUTICAL SUBMARKETS: A BAYESIAN PANEL PROBIT ANALYSIS
进入医药子市场:贝叶斯面板Probit分析
SUMMARY We study entry into pharmaceutical submarkets by using a dynamic panel probit model. We develop a Bayesian version of Wooldridge's approach to dealing with unobserved heterogeneity. We distinguish between greenfield entry (entry with first product) and undifferentiated entry, which may take the form of introducing further products. We extend the standard reduced form model to consider company size in the submarket and across all submarkets. We find that greenfield…