Why Does the Law of One Price Fail? An Experiment on Index Mutual Funds

Experimental subjects allocate $10,000 across four S&P 500 index funds. Subject rewards depend on the chosen portfolio’s subsequent return. Because the investments are not actually intermediated by the fund companies, portfolio returns are unbundled from non-portfolio services. The optimal portfolio therefore invests 100% in the lowest-cost fund. Nonetheless, subjects overwhelmingly fail to minimize fees. When we make fees transparent and salient, portfolios shift towards cheaper funds, but fees are still not minimized. Instead, subjects place high weight on normatively irrelevant historical returns. Subjects who choose high-cost index funds are relatively much less confident about their asset allocation choices.

Mental Accounting in Portfolio Choice: Evidence from a Flypaper Effect

Consistent with mental accounting, we document that investors sometimes choose the asset allocation for one account without considering the asset allocation of their other accounts. The setting is a firm that changed its 401(k) matching rules. Initially, 401(k) enrollees chose the allocation of their own contributions, but the firm chose the match allocation. These enrollees ignored the match allocation when choosing their own-contribution allocation. In the second regime, enrollees simultaneously selected both accounts’ allocations, leading them to mentally integrate the two. Own-contribution allocations before the rule change equal the combined own- and match-contribution allocations afterwards, whereas combined allocations differ sharply across regimes.

$100 Bills on the Sidewalk: Suboptimal Investment in 401(k) Plans

It is typically difficult to determine whether households invest optimally. But sometimes, investment incentives are strong enough to create sharp normative restrictions. We identify employees at seven companies who are eligible to receive employer matching contributions in their 401(k) and can make penalty-free withdrawals for any reason. For these employees, contributing less than the match threshold is a dominated action that violates the no-arbitrage condition. Nevertheless, between 20% and 60% contribute below the threshold, losing as much as 6% of their annual pay. Providing employees with information about the free lunch they are foregoing fails to raise contribution rates.

How Does Simplified Disclosure Affect Individuals' Mutual Fund Choices?

We use an experiment to estimate the effect of the SEC's Summary Prospectus, which simplifies mutual fund disclosure. Our subjects chose an equity portfolio and a bond portfolio. Subjects received either statutory prospectuses or Summary Prospectuses. We find no evidence that the Summary Prospectus affects portfolio choices. Our experiment sheds new light on the scope of investor confusion about sales loads. Even with a one-month investment horizon, subjects do not avoid loads. Subjects are either confused about loads, overlook them, or believe their chosen portfolio has an annualized log return that is 24 percentage points higher than the load-minimizing portfolio.

Defined Contribution Pensions: Plan Rules, Participant Decisions, and the Path of Least Resistance

We assess the impact on savings behavior of several different 401(k) plan features, including automatic enrollment, automatic cash distributions, employer matching provisions, eligibility requirements, investment options, and financial education. We also present new survey evidence on individual savings adequacy. Many of our conclusions are based on an analysis of micro-level administrative data on the 401(k) savings behavior of employees in several large corporations that implemented changes in their 401(k) plan design. Our analysis identifies a key behavioral principle that should partially guide the design of 401(k) plans: employees often follow 'the path of least resistance.' For better or for worse, plan administrators can manipulate the path of least resistance to powerfully influence the savings and investment choices of their employees.

Simplification and Saving

The daunting complexity of important financial decisions can lead to procrastination. We evaluate a low-cost intervention that substantially simplifies the retirement savings plan participation decision. Individuals received an opportunity to enroll in a retirement savings plan at a pre-selected contribution rate and asset allocation, allowing them to collapse a multidimensional problem into a binary choice between the status quo and the pre-selected alternative. The intervention increases plan enrollment rates by 10 to 20 percentage points. We find that a similar intervention can be used to increase contribution rates among employees who are already participating in a savings plan.

Behavioral Economics Perspectives on Public Sector Pension Plans

We describe the pension plan features of the states and the largest cities and counties in the U.S. Unlike in the private sector, defined benefit (DB) pensions are still the norm in the public sector. However, a few jurisdictions have shifted towards defined contribution (DC) plans as their primary savings plan, and fiscal pressures are likely to generate more movement in this direction. Holding fixed a public employee's work and salary history, we show that DB retirement income replacement ratios vary greatly across jurisdictions. This creates large variation in workers' need to save for retirement in other accounts. There is also substantial heterogeneity across jurisdictions in the savings generated in primary DC plans because of differences in the level of mandatory employer and employee contributions. One notable difference between public and private sector DC plans is that public sector primary DC plans are characterized by required employee or employer contributions (or both), whereas private sector plans largely feature voluntary employee contributions that are supplemented by an employer match. We conclude by applying lessons from savings behavior in private sector savings plans to the design of public sector plans.