Abstract
In the paper, I examine free entry in homogeneous product markets and its social efficiency. Previous research on free entry in homogeneous product markets has shown that under Cournot oligopoly with fixed setup costs the free entry equilibrium always delivers excessive entry.
In contrast, I demonstrate in this paper that free entry along with excessive entry might also lead to a socially insufficient number of firms when a demand parameter uncertainty is considered. My findings support the validity of the traditional wisdom in industrial organization that free entry is desirable for social efficiency and call for revision of restrictive entry regulation practices which been based on previous research findings.