Household Portfolios and Retirement Saving over the Life Cycle
利用2006至2018年美国中产阶级投资者的账户数据，研究发现股票投资占比上升10%且与年龄相关，养老金保护法案通过将目标日期基金设为默认选项，使年轻工人增加股票投资、年长工人减少，而缴费率变化不大。
ABSTRACT Using account‐level data on millions of U.S. middle‐class investors over 2006 to 2018, we characterize the share of investable wealth that they hold in the stock market over their working lives. Relative to the 1990s, this share has both risen by 10% and become age‐dependent. The Pension Protection Act (PPA)—which allowed target date funds (TDFs) to be default options in retirement plans—played an important role: younger (older) workers starting at a firm after TDFs became the default option post‐PPA invested more (less) in stocks, in line with the TDF glidepath. In contrast, contribution rates changed little following the PPA.