Caused largely by the recent technological changes towards digitalization, infrastructure investment in network industries has become the main issue for regulatory intervention. In this paper, we study the impact of co-investment between an incumbent and an entrant on the roll-out of network infrastructures under demand uncertainty. We show that if the entrant can wait to co-invest until demand is realized, the incumbent’s investment incentives are reduced, and total coverage can be lower than in a benchmark with earlier co-investment. We consider two remedies to correct these distortions: (i) co-investment options purchased ex ante by the entrant from the incumbent, and (ii) risk premia paid ex post by the entrant. We show that co-investment options cannot fully reestablish total coverage, while premia can do so in most cases, though at the cost of less entry. Finally, we show that an appropriate combination of ex-ante and ex-post remedies can improve welfare.

主要是由于近期向数字化方向发展的技术变革，网络行业的基础设施投资已成为监管干预的主要问题。在本文中，我们研究了在需求不确定的情况下，现有企业和进入者之间的共同投资对网络基础设施推出的影响。我们表明，如果进入者可以等到需求实现后再共同投资，则在职者的投资激励就会减少，并且总覆盖范围可能低于具有早期共同投资的基准。我们考虑了两种补救措施来纠正这些扭曲：(i)进入者事先从现任者那里购买的共同投资期权，以及 (ii)事后支付的风险溢价由入境者。我们表明，共同投资选项不能完全重新建立总覆盖范围，而在大多数情况下，溢价可以这样做，但代价是较少的进入。最后，我们表明事前和事后补救措施的适当组合可以提高福利。