With communications satellites, the cost is no different if one firm supplies long-distance calls or if many firms do so. So the industry evolved from a natural monopoly to a competitive market.
这是344页的第八题的答案。可是除非在完全竟争市场只有每个企业成本曲线相同，长期均衡才会是都以最低成本生产，因此感觉上面的答案有点问题。
请教大家的看法。谢谢！