Taxing Systemic Risk

Topics - Macroeconomics

${ numberSection } ${ text }
Taxing Systemic Risk

Chapter in Regulating Wall Street (Wiley, 2011)

Current financial regulations seek to limit each institution’s risk. However, unless financial institutions internalize the external costs of systemic risk, they will have the incentive to take risks that are borne by others in the economy. That is, each individual firm may take actions to prevent its own collapse but not necessarily the collapse of the system. In this sense, the institution’s risk is a negative externality on the system.

We advocate that systemic risk of the financial sector needs to be regulated, using a measure of an individual financial firm’s contribution to systemic risk. We propose that each financial firm should be charged a “tax” based on its expected loss during a systemic crisis. In our preferred approach, individual firms would be required to buy contingent capital insurance against losses incurred during systemic crises. The cost of this insurance determines the firm’s systemic risk tax.

We discuss why a joint private-public provision of such insurance has the right incentive properties to get the financial sector to internalize systemic risk. We provide an example of how such a systemic risk tax could be calculated and also discuss its relationship to other contingent capital proposals such as forced debt-for-equity conversions.

Overall, the main advantages of this approach are: (i) it forces regulators and financial firms to deal explicitly with systemic risk; (ii) it is based on tools tested and well understood by the private sector; and (iii) it reduces moral hazard in that it provides incentives for regulated firms not to contribute excessively to systemic risk.

AQR Capital Management, LLC, (“AQR”) provide links to third-party websites only as a convenience, and the inclusion of such links does not imply any endorsement, approval, investigation, verification or monitoring by us of any content or information contained within or accessible from the linked sites. If you choose to visit the linked sites, you do so at your own risk, and you will be subject to such sites' terms of use and privacy policies, over which has no control. In no event will AQR be responsible for any information or content within the linked sites or your use of the linked sites.

The information contained herein is only as current as of the date indicated, and may be superseded by subsequent market events or for other reasons. The views and opinions expressed herein are those of the author and do not necessarily reflect the views of AQR Capital Management, LLC, its affiliates or its employees. This information is not intended to, and does not relate specifically to any investment strategy or product that AQR offers. It is being provided merely to provide a framework to assist in the implementation of an investor’s own analysis and an investor’s own view on the topic discussed herein. Past performance is not a guarantee of future results.


Hypothetical performance results have many inherent limitations, some of which, but not all, are described herein. The hypothetical performance shown was derived from the retroactive application of a model developed with the benefit of hindsight.  Hypothetical performance results are presented for illustrative purposes only.


Diversification does not eliminate the risk of experiencing investment loss.


Certain publications may have been written prior to the author being an employee of AQR.

This material is intended for informational purposes only and should not be construed as legal or tax advice, nor is it intended to replace the advice of a qualified attorney or tax advisor.


AQR Capital Management is a global investment management firm, which may or may not apply similar investment techniques or methods of analysis as described herein. The views expressed here are those of the authors and not necessarily those of AQR.