1. Introduction
Since the passage of the Employee Retirement Income Security Act in 1974, a shift in
the US private pension system away from defined benefit (DB) plans and towards
defined contribution (DC) plans has been well documented[1]. This shift has recently accelerated and gained notoriety as many large, financially sound, high-profile
companies such as Verizon, IBM, Motorola, and Sears announced decisions to freeze
their DB plans in the past few years[2]. While freezing a DB plan and replacing it with
a DC (401-K type) plan was not uncommon in the 1980s and 1990s, it was a rare event
among large plan sponsors prior to the twenty-first century (Munnell and Soto, 2007).