This paper introduces a formulation of the optimal network compression problem for financial systems. This general formulation is presented for different levels of network compression or rerouting allowed from the initial interbank network. We prove that this problem is, generically, NP-hard. We focus on objective functions generated by systemic risk measures under shocks to the financial network. We use this framework to study the (sub)optimality of the maximally compressed network. We conclude by studying the optimal compression problem for specific networks; this permits us to study, e.g., the so-called robust fragility of certain network topologies more generally as well as the potential benefits and costs of network compression. In particular, under systematic shocks and heterogeneous financial networks the robust fragility results of Acemoglu, Ozdaglar, and Tahbaz-Salehi (2015) no longer hold generally.

本文介绍了金融系统最优网络压缩问题的公式。这个一般公式是针对不同级别的网络压缩或初始银行间网络允许的重新路由而提出的。我们证明这个问题通常是 NP-hard 问题。我们关注金融网络受到冲击时系统性风险措施所产生的目标函数。我们使用这个框架来研究最大压缩网络的（次）最优性。我们通过研究特定网络的最佳压缩问题得出结论；这使我们能够更广泛地研究某些网络拓扑的所谓鲁棒性脆弱性，以及网络压缩的潜在收益和成本。尤其，