The book discusses Defined Benefit and Defined Contribution Pension plans (401k & 403b) and says that there are more Defined Contribution plans than Defined Benefit plans, but that there are more participants in Defined Benefit plans. This is a relatively recent (over the last 20 years) phenomenon. Companies have been moving away from Defined Benefit plans in favor of Defined Contribution plans.
Why has this shift been taking place? Why do you think that there are more participants in Defined Benefit plans?
Be sure to rely on sources and cite your references in APA format.