James Poterba, Steven Venti, David A. Wise. 2013. The financial crisis and saving in personal retirement accounts. National Bureau of Economic Research

www.nber.org/aging/rrc/papers/onb13-02

Abstract: Personal retirement accounts (PRAs), especially 401(k) plans, have become an increasingly important mode of retirement saving. This paper provides new evidence on the effect of the recent financial crisis, and the associated decline in employment, on PRA saving. We particularly examine how these effects vary across demographic groups. We explore how crisis-related changes in employment and earnings affected PRA balances. We do this by estimating the effect of the crisis on these outcomes and then by considering how PRA ownership and balances depend on employment and earnings as well as other covariates. To assess the effect of the crisis we estimate the relationship between age (and other covariates) and the labor market and PRA outcomes in years prior to the crisis (2004-2006) and then estimate how these relationships change during the crisis period (2008-2010). We find very few statistically significant differences in the parameter estimates for the pre-crisis and the crisis periods. We use the model to predict age profiles of employment rates, earnings given employment, PRA ownership, and PRA balances given ownership in the pre-crisis and crisis periods. We give special attention to the relationship between education and PRA ownership and balances.

摘要：个人退休账户(PRAs)，特别是401(k)计划，已经成为退休储蓄中一种越来越重要的模式。这篇文章给出了有关最近金融危机对个人退休账户的影响与相关联的就业衰减的新证据。我们还特别检验了这些影响在不同人群中的差异。我们探索了与危机相关的雇佣与收入的改变是如何影响个人退休账户余额的。我们通过估测危机对就业、收入与其他协变量的影响来进行上述的研究。为了测算危机的影响，我们测量了在危机之前(2004-2006) 年龄（及其他协变量）、劳动力市场与个人退休账户成果之间的关系，然后测量了在危机中(2008-2010) 这些关系发生了怎样的改变。我们在对比危机前与危机中的参数分析中没有发现统计上明显的不同之处。我们使用了模型来预测危机前与危机中的雇佣率年龄结构、有偿雇佣、个人退休账户所有量以及个人退休账户余额。对教育与个人退休账户所有权和余额之间的联系，我们给出特别的关注。

数据来源：

Health and Retirement Study Data: Health and Retirement Study (HRS), a nationally representative sample of adults over the age of 50 in the United States

The Financial and Employment Crises：S&P 500 index and the Case-Shiller housing price index

Health Measure：Health index constructed from responses to 27 health-related questions concerning self-reported functional limitations, health conditions, and medical care usage

Education and the Propensity to Save：运用自己开发的工具测量

研究方法：计量回归

Conclusion: We have estimated the effect of the financial and employment crises on PRA ownership and PRA account balances. We have also estimated the effect of the crises on the employment and earnings of older Americans. We caution that the HRS data we use to measure the “crisis” response are from 2008 and 2010. The 2008 data may pre-date the trough of the crisis and the 2010 data may post-date the trough. By 2010 stock prices had rebounded dramatically, but housing prices and most labor market indicators were still well below pre-crisis levels. The estimates reveal several noticeable patterns. First, the employment rate for men age 50 to 60 was 3 percentage points lower during the crisis than before the crisis, but the employment rate at retirement ages (61 to 67) was greater during the crisis than in the pre-crisis period. The lower rate at younger ages is likely the result of job loss during the crisis and the higher employment rate at traditional retirement ages was apparently due to delayed retirement.

For men in their fifties, PRA ownership was greater during the crisis than in the pre-crisis period. This may have resulted simply from the secular increase in PRA ownership – persons at a given age in the pre-crisis period belong to an older birth cohort than persons who reached the same age in the crisis period, and they were less likely to have access to 401(k) plans in the workplace than workers a few years younger. In addition for men 65 and older, PRA balances were noticeably greater during the crisis period than during the pre-crisis years. We do not have good data on contributions and withdrawals that would allow us to determine the source of PRA account growth.

To determine the crisis period effects we estimated the relationship between each outcome and a set of covariates including the additional effect of each covariate in the crisis period. Although most of the additional “crisis” effects were not statistically significant, many of the baseline estimates are of particular interest. The most striking findings are the very strong relationships between the level of education and PRA ownership and PRA account balances. For men, the increase in the probability of PRA ownership associated with having a high school degree is over nine times as great as the increase associated with a $10,000 increment in earnings. The effect of a college degree is over 15 times as large as the increase associated with a $10,000 increment in earnings. Controlling for earnings, the association between education and the PRA balance is also very large. While a $10,000 increment in earnings is associated with about a $6,000 increment in the PRA balance, the effect of education (compared to those without a high school degree) ranges from about $51,000 for those with a high school degree to almost $250,000 for those with a college or post-college degree.

We interpret the relationship between PRA balances and education, controlling for earnings and health status as consistent with education as a proxy for the propensity to save. As an indicator of the propensity to save we calculated the ratio of wealth to lifetime earnings for all sample members who had linked Social Security earnings records. Given any level of lifetime earnings, the ratio of accumulated assets to lifetime earnings is, on average, 0.13 for persons with less than a high school degree, 0.16 for those with a high school education, 0.23 for persons with some college, and 0.47 for persons with a college degree or more. Education is also very strongly related to PRA ownership. The relationship of education of PRA ownership is surely due in large part to the employment of persons with low education in low-paying and high-turnover jobs that tend not to offer 401(k) plans.

结论：我们估测了金融与就业危机对个人退休账户所有量和账户余额的影响。我们也估测算了危机会年长的美国人就业和收入的影响。我们使用了2008到2010年的HRS数据衡量“危机”反应。2008年的数据也许危机前的数据，而2010年的数据则在危机之后。截至2010年股票价格急剧反弹，但房价与大多数劳动力市场指示指标仍然低于危机前水平。测算揭示了几项值得注意的内容。首先，50-60岁之间男子在危机中的就业率要比危机前低3个百分点名单退休年龄人（61-67岁）的就业率就要高于危机前。年轻人的低就业率也许是金融危机中工作职位数减少导致的。且传统退休年龄的高就业率明显是因为延迟退休。

对于50岁的人来说，危机中个人退休账户的拥有量要比危机之前多。这也许仅仅是因为个人退休账户数量的长期增长——在危机之前特定年龄的人们于危机中特定年龄的人相比，属更老的群体，并且他们比年轻一些的工人更少地接触到401(k)计划。除了65岁以上的人，个人退休账户余额在危机时段中比危机之前大很多。我们没有好关羽存取款的数据来支持我们确定个人退休账户增长的来源。

为了确定危机的影响，我们测算了每个产出与协变量组间的关系，包括危机期间每个协变量的额外影响。尽管大多数额外的“危机”影响在统计上并不是特别重要，很多有关基线的估测却非常有趣。最有意义的研究成果是：教育水平、个人退休账户所有量与个人退休账户余额间的强力联系。对人来讲，拥有高中学历的人个人退休账户的收益相当于增加$10,000收入的9倍。而拥有大学学历则意味着该倍数为15倍。当我们控制收入，教育与个人退休账户余额间的联系也非常大。当增加$10,000收入相当于增加$6,000的个人退休账户余额，教育的影响（与那些没有高中学历的人相比）从高中学历的人可以获得$51,000到大学或大学预科学历的人可以获得几乎$250,000。

控制了收入和健康状况，与作为代表储蓄倾向的教育一致，我们揭示了个人退休账户余额与教育的关系。作为储蓄倾向的指示指标，我们计算了所有具有社会保险收入记录的所有样本的生命总收入的财富率。对任何一个生命收入水平来说，累计财产成为生命收入的平均率，对高中以下学历的人是0.13，对高中学历的人是0.16，对进入大学学习过的人是0.23，对大学及以上学历的人是0.47。教育与个人退休账户所有量也有很大关系。他们之间的关系是因为低受教育程度、高职业转换的人更可能负担不起401(K)计划。

（By 潘一坤)