What Is a Barrier to Entry?
梳理经济学文献中关于进入壁垒的多种定义，提出分类体系来澄清混乱，并用它评估规模经济和沉没成本构成的壁垒性质。
The present article is an attempt to resolve the controversies concerning the concept of barriers to entry. We begin by contrasting the definitions of an entry barrier proposed in the economics literature. We then introduce a classification system to clear up the existing confusion, and we employ it to assess the nature of the barriers posed by scale economies and sunk costs.