Youngkyun Park

The Influence of Plan Demographics on Contribution Behavior of 401(K) Participants

This article examines the influence of plan demographics, which is defined as the salary and tenure composition of a plan, on contribution behavior of 401(k) participants. Results using a large sample of 401(k) plans show that plan demographics influence participant contribution rates directly or through interaction with individual demographic characteristics. A participants contribution rate can be varied by 1.6–3.0 percentage points for each age between 25 and 64, depending on what plan demographics she is exposed to. In addition, for the decision to contribute the maximum allowed amount, plan demographics significantly interact with individual demographic characteristics.

Variation of Retirement Income from 401(k) Plan Sponsors’ Target-Date Fund Choices?

This article examines how the variability of target-date fund (TDF) participants’ retirement income resulting from plan sponsors’ TDF choices can be reduced by a qualified automatic contribution arrangement (QACA) that reflects plan demographics. Using Monte Carlo simulations, the article finds that a QACA where a maximum employee contribution rate is based on plan demographics can not only increase participant retirement income (measured as a success rate or probability of achieving a target replacement rate), but also reduce its variability.