Stress Testing Financial Networks: The Case of CCPs

Following the crisis of 2007-09, in which AIG’s bilateral derivatives trades played a notable role, the G20 leaders called for central clearing of standardized derivatives. The resulting shift has been dramatic: central counterparties (CCPs) now clear about three-fourths of interest rate contracts, up from less than one-fourth a decade earlier (see Faruqui, Huang and Takáts).

By substituting a CCP as the buyer to every seller and the seller to every buyer, central clearing mutualizes and can—with appropriate margining, trade compression, position liquidation procedures, and reporting—reduce counterparty risk (see Tuckman). CCPs also contribute to financial resilience by promoting uniform margin standards, reducing collateral and liquidity needs, and making risk concentrations (like that of AIG in the run-up to the crisis) more transparent.

At the same time, the shift to central clearing has concentrated risk in the CCPs themselves. Reflecting economies of scale and scope, as well as network externalities, a few CCPs serving global clearing needs have grown enormous. For example, as of the last report at end-September 2018, open interest at LCH Clearnet exceeded $250 trillion. Moreover, the clearing activity of some CCPs lacks any short-run substitute. As a result, to avoid disrupting large swathes of the global financial system, any recovery or resolution plan for these CCPs must ensure continuity of service (see CCP Resolution Working Group presentation to the OFR Financial Research Advisory Committee). Finally, CCPs are the most interconnected intermediaries on the planet, making them channels for transmission and amplification of financial distress within and across jurisdictions. As then-Governor Powell clearly states in the opening quote, the safety of CCPs is central to the resilience of the global financial system.

We and Richard Berner have been studying how regulators use stress tests (see our earlier posts here and here) to assess the resilience of financial networks, including banks and nonbanks. In our joint work, we focus on CCPs due to their centrality, their extreme interconnectedness and their lack of substitutability. This post is based on our research….

Size is Overrated

This month, in the guise of supporting community banks, the U.S. Senate passed a bill (S.2155) that eases regulation of large banks. We share the critics’ views that this wide-ranging dilution of existing regulation will reduce the resilience of the U.S. financial system.

In its best known and most publicized feature, the Senate bill raises the asset size threshold that Dodd-Frank established for subjecting a bank to strict scrutiny (such as the imposition of stress tests, liquidity requirements, and resolution plans) from $50 billion to $250 billion. In this post, we examine the role of asset size in determining the systemic importance of a financial intermediary. It turns out that (aside from the very largest institutions, where it does in fact dominate) balance sheet size is not a terribly useful indicator of the vulnerability a bank creates. We conclude that Congress should ease the strict oversight burden on institutions that pose little threat to the financial system without raising the Dodd-Frank threshold dramatically.

Judge makes an elegant proposal for accomplishing this. For institutions with assets between $100 billion and $250 billion, Congress should just flip the default. Rather than obliging the Fed to prove a mid-sized bank’s riskiness, give the bank the opportunity to prove it is safe. This approach gives institutions the incentive to limit the systemic risk they create in ways that they can verify. It also sharply reduces the risk of litigation by banks that the Fed deems risky...

Commentary

Money, Banking, and Financial Markets