Wharton Pension Research Council Working Papers

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Working Paper

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The Pension Benefit Guaranty Corporation (PBGC) insures private sector defined benefit (DB) pension plans when an employer becomes insolvent and is unable to pay its pension liabilities. In principle, the insurance premiums collected by PBGC should be sufficient to cover potential losses; this would ensure that PBGC could pay the insured benefits of terminated pension plan without additional external funding (e.g. from taxpayers). Therefore, the risk exposure of the PBGC from insuring DB pension plans arises from the probability of employer insolvencies; and the terminating plans’ funding status (the excess of the value of insured plan liabilities over plan assets). This paper focuses on only the second component, namely the impact of plan underfunding for the operation of the PBGC. When a DB plan is fully funded, the PBGC’s risk exposure for an ongoing plan is low even if the plan sponsor becomes insolvent. Thus the questions most pertinent to the PBGC are what key risk factors can produce underfunding in a DB plan, and how can these risk factors be quantified? We explore the most important risk factors that produce DB pension underfunding, namely investment risk and liability risk. Both are interrelated and must be considered simultaneously in order to quantify the risk exposure of a DB pension plan. We propose that an integrated risk management model (an Integrated Asset/Liability Model) can help better understand DB pension plan funding risk. We also examine the Pension Insurance Modeling System developed by the PBGC in terms of its own use of some of the building blocks of an integrated risk management model.

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Copyright/Permission Statement

All findings, interpretations, and conclusions of this paper represent the views of the authors and not those of the Wharton School or the Pension Research Council. ©2013 Pension Research Council of the Wharton School of the University of Pennsylvania. All rights reserved.


The research reported herein was pursuant to a grant from the U.S. Social Security Administration (SSA) funded as part of the Retirement Research Consortium (RRC); the author also acknowledges support from The Pension Research Council at The Wharton School. All findings and conclusions expressed are solely those of the author and do not represent the views of the SSA or any agency of the federal government, the MRRC, the PRC, or The Wharton School at the University of Pennsylvania.

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Date Posted: 26 June 2019