Central Clearing and Collateral Demand

Central Clearing and Collateral Demand

Procyclicality of CCP Margin Models: Systemic Problems Need Systemic Approaches

How did the Greek credit event impact the credit default swap market?

A simple overlapping generations model is used to characterize the effects of initial margin requirements on the volatility of risky asset prices. Investors are assumed to exhibit heterogeneous preferences for risk-bearing, the distribution of which evolves stochastically across generations. This framework is used to show that imposing a binding initial margin requirement may either increase or decrease stock price volatility, depending upon the microeconomic structure behind fluctuations in economy-wide average risk-bearing propensity. The ambiguous effect on volatility similarly arises when the source of heterogeneity is noise trader beliefs. BEYOND THEIR PRUDENTIAL FUNCTIONS, the effects of initial margin requirements on securities markets are not well understood. Many have argued, based upon empirical findings, that the level of margin requirements has no discernable impact on stock price behavior.' Nevertheless, the view that high margin requirements dampen speculative excesses and reduce excess price volatility remains popular. The simultaneous existence of such views highlights the uncertainty surrounding this issue. In fact, there exists no rigorously articulated theory of the interaction between initial margin requirements and stock prices and their returns' characteristics. In this paper we construct a simple dynamic model useful for characterizing the effects of initial margin requirements on security prices and returns. To analyze the impact of margins, we introduce investor heterogeneity into an otherwise simplified overlapping generations (OLG) economy.2 The OLG models are constructed so that each generation displays heterogeneous preferences or beliefs, the distribution of which evolves stochastically across generations. In each of two heterogeneous taste models we consider there are two types of agents, one of which is more risk tolerant than the other. In one model, the

This article investigates the relationship between initial margin requirements and stock return volatility. Volatility is measured using a GARCH in Mean model. We find no evidence of an empirical relationship between margin requirements and the volatility of the S&P 500 index portfolio's excess returns. Evidence from short-sale data, and model sensitivity analysis are presented which support the hypothesis of no margin-volatility relationship. The results are consistent with the intertemporal CAPM model of Merton (1973) with an aggregate relative risk aversion measure of 4.1. In addition, we find evidence of long-term memory in conditional return distributions' volatility.

IN MY judgment," maintained William McChesney Martin, Jr., Chairman of the Board of Governors, Federal Reserve System, "we can never under the present margin regulations have the same result that occurred in terms of a financial crash in 1929 through undermargined accounts, low margins resulting in a financial debacle."' A widely used elementary economics textbook claimed, "Margin requirements have exercised an important restrictive influence on security speculation, as contrasted with the uncontrolled period of the late 1920's... Nearly everyone agrees that Federal Reserve margin requirements exercise a healthy restraint on speculative stock purchases in a boom" (Bach, 1963, p. 116). But what evidence is there that margin requirements have the effects claimed? At the December meetings of the American Economic Association, George J. Stigler, in the Presidential address, called on economists to test their assumptions that state regulation of private activity has indeed been successful (Stigler, 1965). This article brings together some data on the efficacy of margin requirements. While the figures can only be considered preliminary, and more data should be collected to test margin requirements, the data that are available and presented here indicate that not one of the aims of the legislation establishing margin requirements has been accomplished.2

The Interconnectedness and Systemic Importance in the U.S. CDS Market

The delivery option in credit default swaps

The introduction of mandatory margining for non-cleared derivatives portfolios has major implications for the pricing and risk measurement of over-the-counter (OTC) derivatives. In particular, a model for estimating future initial margin requirements is necessary to enable the calculation of relevant pricing adjustments, net counterparty credit exposures and credit capital requirements. Existing literature on the topic suggests a model that makes use of regression techniques, but little detail is available on the predictive quality of these models within a Monte Carlo simulation framework. We review these regression-based initial margin models in detail and compare their output against the actual margin requirements measured by the International Swaps and Derivatives Association standard initial margin model (ISDA SIMM) methodology. We observe that the models generally perform well for single trades but show some degradation for larger diversified portfolios. We investigate potential extensions and improvements to the model, along with examining some additional ‘conservatism’ features that may have application in the context of credit exposure measurement. The initial margin modelling approaches discussed here are similarly applicable to centrally cleared or exchange-traded portfolios.

Estimating a Covariance Matrix for Market Risk Management and the Case of Credit Default Swaps

Credit default swaps (CDSs) are term insurance contracts written on traded bonds. This review studies the economics of CDSs using the economics of insurance literature as a basis for analysis. It is alleged that trading in CDSs caused the 2007 credit crisis, and therefore trading CDSs is an evil that needs to be eliminated or controlled. In contrast, I argue that the trading of CDSs is welfare increasing because it facilitates a more optimal allocation of risks in the economy. To perform this function, however, the risk of the CDS seller's failure needs to be minimized. In this regard, government regulation imposing stricter collateral requirements and higher equity capital for CDS traders needs to be introduced.

Hazardous Hedging: The (Unacknowledged) Risks of Hedging with Credit Default Swaps

Chapter 6 - Credit Default Swaps

CCP Clearing Demystified

Initial margin requirements represent: (1) a cost impediment to the wealth constrained investor and (2) a potential way of mitigating excessive volatility. However, prior empirical research finds that margins are not an effective tool in reducing volatility. We consider the possibility that margins primarily affect certain stocks and investors. Specifically, we test whether margins affect individuals who, as a group, we believe to be the investors most affected when margin requirements change. Our initial empirical tests, however, do not support this contention.