Asset accumulation in later life is a pressing issue in Japan due to the growing gap between life expectancy (87.14 years for women, 81.09 years for men in 2023) and the retirement age (65 or less). This gap heightens financial insecurity, emphasizing the need to meet asset goals by 65. Hyperbolic discounting, driven by present-biased preferences, often hinders this process, but empirical evidence for those aged 65 and older remains limited. Moreover, prior research has overlooked the varying impacts of hyperbolic discounting across different wealth levels. This study addresses these gaps by analyzing data from 6709 active Japanese investors aged over 65 (2023 wave) using probit regression. Wealth thresholds are categorized into four levels: JPY 20 million, JPY 30 million, JPY 50 million, and JPY 100 million. The results show that hyperbolic discounting significantly impairs asset accumulation at the JPY 100 million level but not at lower thresholds. This effect likely reflects the complex nature of hyperbolic discounting, which primarily affects long-term savings and investments. The findings underscore the importance of addressing hyperbolic discounting in later-life financial planning. Recommendations include implementing automatic savings plans, enhancing financial literacy, and incorporating behavioral insights into planning tools to support better asset accumulation outcomes.

Obesity is a major global health concern related to chronic diseases and rising healthcare costs. While previous studies focused on diet habits, environmental issues, and physical activity, financial literacy remains an overlooked factor in weight management. This study examined the relationship between financial literacy and the body mass index (BMI), using financial literacy as a proxy for rational health decision-making. A quantitative approach was employed, where linear regression analyzed the BMI as a continuous variable and a probit regression assessed overweight, normal weight, and underweight categories. A nationwide survey, the Preference Parameter Study, conducted by Osaka University, Japan, in the United States, provided the data for this study. The results indicate a significant negative association between financial literacy and the BMI, with higher financial literacy linked to a lower BMI and a greater likelihood of maintaining a normal weight. The key control variables, including impatience, gender, education, income, and smoking, also significantly affected the BMI. These findings reflect a strong correlation between financial literacy and the weight status; however, due to data limitations, causal inferences could not be made. We acknowledge the potential endogeneity and the cross-sectional nature of the data as limitations. Thus, while our results suggest a potential role for financial literacy in promoting rational health behavior, the policy implications should be interpreted with caution. Future research should explore targeted interventions across various demographic groups to maximize the impact.