Working papers

  • Interbank Networks in the Shadows of the Federal Reserve Act

    with Haelim Anderson and Guillermo Ordonez

    Central banks provide public liquidity (through lending facilities and promises of bailouts) with the intent to stabilize the financial system. Even though this provision is restricted to member (regulated) banks, an interbank system can provide indirect access to nonmember (shadow) banks. We construct a model to understand how a banking network may change in the presence of central bank interventions and how those changes affect financial fragility. We provide evidence showing that the introduction of the Fed’s liquidity provision in 1913 increased systemic risk through three channels; it reduced aggregate liquidity, created a new source of financial contagion, and crowded out private insurance for smoothing cross-regional liquidity shocks (manifested through the geographic concentration of networks).


  • Network Hazard and Bailouts

    (Best job market paper runner-up prize, Finance Theory Group)

    This paper characterizes strongly stable networks under general threshold contagion. Among other applications, the theory is applied to interbank lending and financial contagion wherein a government can intervene to stop contagion. In the absence of intervention, banks form disjoined clusters to minimize contagion. In the presence of intervention, banks become less concerned with the counterparties of their counterparties, which we dub network hazard. Network hazard allows some banks to become systemically important and gives the network a core-periphery structure. The counterparty risk of a large part of the economy becomes correlated through the core banks’ solvency. Core banks serve as a buffer against contagion when solvent and an amplifier of contagion when insolvent. As such, bailouts create welfare volatility and increase systemic risk via network hazard. It is shown that network hazard is a novel force distinct from moral hazard. Results are historically relevant to the pyramiding of reserves and the establishment of the Federal Reserve.


  • Insider Networks

    with Michael Junho Lee

    How do insiders respond to regulatory oversight? History suggests that they form sophisticated networks to share information and circumvent regulation. We develop a theory of the formation and regulation of information transmission networks. We show that agents with sufficiently complex networks bypass any given regulatory environment. In response, regulators employ broad regulatory boundaries to combat gaming, giving rise to regulatory ambiguity. Tighter regulation induces agents to migrate transmission activity from existing social networks to a core-periphery insider network. A small group of agents endogenously arise as intermediaries for the bulk of information. We provide centrality measures that identify intermediaries.


  • Network Formation and Systemic Risk

    with Rakesh Vohra

    This paper introduces a simple model of endogenous network formation and systemic risk. In the model, firms form joint ventures called ‘links’ which are subsequently subjected to shocks that are either good or bad. Bad shocks incentivize default. Links yield full benefits only if the counterparty does not subsequently default on the project. Accordingly, defaults triggered by bad shocks render firms insolvent and defaults propagate via links. The model yields three insights. First, stable networks with ex-ante identical agents exhibit a core-periphery structure. Second, an increase in the probability of good shocks increases systemic risk. Third, the network formed critically depends on the correlation between shocks to links. As a consequence, an observer who misconceives the correlation will significantly underestimate the probability of systemwide default.