This paper presents a bilateral network formation model that explains why some empirical degree distributions exhibit the increasing hazard rate property (IHRP). In my model, a sequentially arriving node forms a link with an existing node through a bilateral agreement. This newborn node prefers a highly linked node; however, the more links an existing node have, the more the marginal return from an additional link diminishes. I prove that the IHRP emerges if and only if the latter effect prevails over the former. I provide two implications of the IHRP. First, I show that the IHRP is related to the existence of equilibria in network games with strategic complementarities. Second, I fit the model to empirical degree distributions and demonstrate that the IHRP is more likely to be observed in social and economic networks. For those networks, my model also exhibits a higher data-fitting performance than other distributions.

本文提出了一个双边网络形成模型，该模型解释了为什么一些经验程度分布表现出增加的危险率特性（IHRP）。在我的模型中，顺序到达的节点通过双边协议与现有节点形成链接。这个新生节点更喜欢高度链接的节点。但是，现有节点拥有的链接越多，附加链接的边际收益就越减少。我证明，只有在后者的影响高于前者的情况下，IHRP才会出现。我提供了IHRP的两个含义。首先，我证明了IHRP与具有战略互补性的网络游戏中均衡的存在有关。其次，我将模型拟合到经验程度分布，并证明在社会和经济网络中更可能观察到IHRP。对于那些网络，我的模型还显示出比其他分布更高的数据拟合性能。