摘要：The lack of complete information of the government has been considered as a barrier to
the optimal regulation, as it is well-known in price regulations literature. However, it is not true
for the entry regulation: This paper shows that the performance of the entry regulation under
incomplete information can be better than that under complete information. Under incomplete
information, the incumbent firm would deviate from the monopoly behavior to signal itself as
an efficient type and to trigger entry regulation which prevents excess entry in case that the
incumbent is efficient. As a result, social welfare can be even higher than under complete
information, since not only the optimal post-entry market structure is achieved as under
complete information but the pre-entry price is even lower than that under complete
information.
