Portfolio Allocation over Life-Cycle with Multiple Late-in-Life Saving Motives

Older households face health-related risks, including risk of being in need of long-term care and mortality risk. How these risks affect financial portfolio choice of households depends on household preferences for long-term care and bequest. Using linked survey-administrative data on clients of a mutual fund company, this paper finds that the desire to have enough resources for long-term care and bequests are overall strong but also heterogeneous across households. The estimated relationship between actual stock share of households and the strength of these preferences is qualitatively similar but quantitatively much weaker compared to the predictions from the life-cycle model with the estimated preference heterogeneity. Based on the predictions from the model, this paper discusses what financial instruments would better meet the needs of households

Forced Retirement Risk and Portfolio Choice

The literature on the effect of labor income on portfolio choice overlooks that workers face a risk of being forced to retire before their planned retirement age. Using the Health and Retirement Study data, this paper finds the forced retirement risk to be significant and also highly correlated with stock market fluctuations. A life-cycle portfolio choice model with the estimated forced retirement risk shows that the labor income of those subject to the risk of forced retirement becomes stock-like as individuals approach retirement. Therefore, contrary to conventional wisdom, those who are still working but close to retirement should have a lower share of risky assets in their financial portfolios than retirees do. Given that most financial assets are held by middle-aged households, this finding gives an alternative explanation to the risk premium puzzle

Heterogeneity in Expectations, Risk Tolerance, and Household Stock Shares

This paper investigates the relationship between stock share and expectations and risk preferences using linked survey responses and administrative records from account holders. The survey allows individual-level, quantitative estimates of risk tolerance and of the perceived mean and variance of stock returns. Estimated risk tolerance, expected return, and perceived risk have economically and statistically significant explanatory power for the distribution of stock shares. Relative to each other, the magnitudes are in proportion with the predictions of benchmark theories, but they are substantially attenuated. MBA graduates have more stable beliefs, more knowledge about their account holdings, and less attenuation

Older Americans Would Work Longer If Jobs Were Flexible

Older Americans, even those who are long retired, have strong willingness to work, especially in jobs with flexible schedules. For many, labor force participation near or after normal retirement age is limited more by a lack of acceptable job opportunities or low expectations about finding them than by unwillingness to work longer. This paper establishes these findings using an approach to identification based on strategic survey questions (SSQs) purpose-designed to complement behavioral data. These findings suggest that demand-side factors are important in explaining late-in-life labor market behavior and may be the most appropriate target for policy aimed at promoting working longer

Quantum Aspects of Massive Gravity II: Non-Pauli-Fierz Theory

We investigate the non-Pauli-Fierz(nPF) theory, a linearized massive gravity with a generic graviton mass term, which has been ignored due to a ghost in its spectrum and the resultant loss of unitarity. We first show that it is possible to use the Lee-Wick mechanism, a unitarization through the decay of a ghost, in order to handle the sixth mode ghost of nPF, and then check for the quantum consistency. Once proven to be consistent, nPF could become a viable candidate for a large distance modification of gravity, because it naturally solves the intrinsic problems that most dark energy/modified gravity models suffer from: It smoothly converges to general relativity at short distances, and the small graviton mass necessary to modify gravity at large scales can be stable under the radiative corrections from the minimal gravity-to-matter coupling.Comment: 1+16pp, accepted for JHE

Heterogeneity in Expectations, Risk Tolerance, and Household Stock Shares: The Attenuation Puzzle

This article jointly estimates the relationship between stock share and expectations and risk preferences. The survey allows individual-level, quantitative estimates of risk tolerance and of the perceived mean, and variance of stock returns. These estimates have economically and statistically significant association for the distribution of stock shares with relative magnitudes in proportion with the predictions of theories. Incorporating survey measurement error in the estimation model increases the estimated associations 2-fold, but they are still substantially attenuated being only about 5% of what benchmark finance theories predict. Because of the careful attention in the estimation to measurement error, the attenuation likely arises from economic behavior rather than errors in variables

Stretchable carbon nanotube charge-trap floating-gate memory and logic devices for wearable electronics

Electronics for wearable applications require soft, flexible, and stretchable materials and designs to overcome the mechanical mismatch between the human body and devices. A key requirement for such wearable electronics is reliable operation with high performance and robustness during various deformations induced by motions. Here, we present materials and device design strategies for the core elements of wearable electronics, such as transistors, charge-trap floating-gate memory units, and various logic gates, with stretchable form factors. The use of semiconducting carbon nanotube networks designed for integration with charge traps and ultrathin dielectric layers meets the performance requirements as well as reliability, proven by detailed material and electrical characterizations using statistics. Serpentine interconnections and neutral mechanical plane layouts further enhance the deformability required for skin-based systems. Repetitive stretching tests and studies in mechanics corroborate the validity of the current approaches. © 2015 American Chemical Society147491sciescopu

Oxide Nanomembrane Hybrids with Enhanced Mechano- and Thermo-Sensitivity for Semitransparent Epidermal Electronics

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