Yoshihiko Kadoya

This study examines the association between self-reported recent investment performance and loneliness among 158,080 individual investors in Japan using the 2025 Survey on Life and Money. Loneliness was measured using three UCLA loneliness items, and investment performance was classified into five self-reported categories. We estimated probit models with break-even performance as the reference category, adjusting for demographic, socioeconomic, financial, and other observed characteristics, and conducted robustness and Wald tests. In the fully adjusted model, slight and considerable profits were associated with 2.23- and 7.34-percentage-point lower probabilities of loneliness, respectively, relative to break-even performance. These negative associations remained statistically significant under alternative definitions of loneliness. In contrast, results for reported losses were less consistent, with considerable losses positively associated with loneliness under some alternative measures. Wald tests rejected coefficient symmetry between considerable profits and considerable losses, but not between slight profits and slight losses. Joint tests did not find statistically significant evidence of differences in investment-performance coefficients by gender or age group. These findings highlight an association between perceived investment outcomes and loneliness, but the cross-sectional design and self-reported measures preclude causal conclusions.

Background: Concerns about increased loneliness during the COVID-19 pandemic have been widely reported. However, long-term trajectories of loneliness remain insufficiently described. Objective: To examine annual trends and five-year transition patterns of loneliness in Japan from 2020 to 2024 using data from a nationwide online panel. Methods: We analyzed data from 1,673 adults who participated in all five annual survey waves from 2020 to 2024 and had complete information on the variables used in the analysis. Loneliness was measured using the three-item UCLA Loneliness Scale. Descriptive statistics were used to estimate annual prevalence and five-year transition patterns. Sensitivity analyses were conducted using a stricter loneliness threshold. Results: The prevalence of loneliness peaked in 2021, declined in 2022, and remained relatively stable from 2022 to 2024. Most respondents demonstrated stable trajectories over five years, either consistently reporting loneliness or consistently not reporting loneliness. A smaller proportion exhibited transient loneliness during the pandemic period. Under the stricter loneliness threshold, the 2021 peak and the predominance of stable over transitional sequences were preserved, although the ranking of specific sequences changed. Conclusions: Among respondents retained in this five-wave online panel, loneliness prevalence peaked in 2021, declined in 2022, and remained relatively stable from 2022 to 2024. Stable trajectories were more common than transitional trajectories. These findings provide descriptive evidence on long-term loneliness patterns but should not be interpreted as nationally representative prevalence estimates.

Dementia is associated not only with clinical and caregiving challenges but also with concerns about future social connectedness, social participation, and resilience. This study examines anticipated social connectedness under dementia, defined as respondents’ self-assessed confidence that they could remain connected to society if they were to develop dementia in the future, and its association with demographic, socioeconomic, and psychological characteristics in Japan. Using data from the 2026 wave of the Survey on Life and Money conducted among Rakuten Securities account holders, we analyze 20,352 respondents aged 18 to 86. Ordered probit models are used as the main specification, with a binary specification employed as a robustness check. The results show that unemployment is negatively associated with anticipated social connectedness under dementia, whereas household income is positively associated with it across several specifications. Family-related variables, including marital status and number of children, also show positive associations in some models, although their relevance differs across gender and age groups. The associations for household financial assets and myopic views of the future are less stable. These findings suggest that anticipated social resilience under dementia may be socially patterned and related to broader socioeconomic circumstances. However, because the analysis is based on cross-sectional survey data from securities account holders and the dependent variable captures self-assessed confidence rather than realized social connectedness among people living with dementia, the results should be interpreted as associations rather than causal effects and should not be generalized mechanically to the broader population.

Inflation expectations are central to monetary policy transmission, yet relatively little is known about whether individuals’ own investment experiences are associated with how they form such expectations across different forecast horizons. This study examines the association between self-reported past investment performance and horizon-specific expected cumulative consumer price changes at the one-, three-, and five-year horizons using a large-scale online survey of 157,523 active Japanese investors. Because the survey asks respondents how consumer prices will change over each horizon, the three- and five-year responses are interpreted as expected cumulative price changes rather than annualized inflation rates. Ordered probit models are estimated while controlling for demographic, socioeconomic, and behavioral characteristics. The results show a horizon-dependent conditional association: self-reported investment performance is not significantly associated with one-year expectations in the full specification, whereas it is positively and significantly associated with three- and five-year expectations. Formal stacked OLS interaction tests indicate that the association differs significantly across horizons, and additional threshold-specific probit models show that the pattern is most evident for moderate inflation-expectation thresholds. The economic magnitudes are statistically precise but modest. Heterogeneity analyses further suggest that the association is weaker among respondents with higher financial literacy and higher assets, and stronger among respondents with a more myopic view of the future. Because the analysis relies on cross-sectional observational data and subjective performance measures, the findings should be interpreted as conditional associations rather than causal effects.

This study examines investor heterogeneity in relative priorities for AI-based financial services using a large-scale survey of Japanese online investors. We use data from the 2026 wave of the “Survey on Life and Money,” administered by Rakuten Securities and Kadoya Lab at Hiroshima University. The final analytical sample comprises 14,432 respondents. Respondents selected their first-, second-, and third-preferred AI-based services from 11 options, which were grouped into five functional categories: administrative procedure proxy services, consultation for troubles and emergencies, education and literacy support, information provision and planning support, and advisory and management for investment. Because respondents were required to select their top three preferred services, the dependent variables capture relative priorities rather than absolute willingness to use AI services. Binary probit and ordered probit models show that investor characteristics are associated with relative priorities across service categories, although the estimated marginal effects are generally modest. Information provision and planning support is more strongly prioritized by male respondents, more-educated respondents, and those with greater household financial assets. Advisory and management services are more strongly prioritized by higher-income and more impatient respondents, while risk aversion is negatively associated with this category. Additional robustness checks suggest that these patterns are not explained entirely by unequal category sizes, although option-level results reveal some within-category heterogeneity. These findings suggest that AI-based financial services should reflect investor heterogeneity while recognizing that service categories may contain diverse underlying functions.

Rapid digitalization has reshaped financial decision-making, and anxiety about later life is an important concern among middle-aged and older investors. Yet it remains unclear whether the traditional Big Three financial knowledge component captures the aspects of financial capability most closely associated with lower anxiety in digital financial environments. This study examines the association between old-age anxiety and digital financial literacy (DFL) components among digitally active Japanese retail investors aged 40–64. Using data from a large-scale survey of 94,695 investors, we estimate ordered probit models to examine overall DFL and its eight subdimensions. While overall DFL is negatively associated with anxiety about life after age 65, decomposing the index reveals substantial heterogeneity across components. The traditional Big Three financial knowledge component does not show a robust independent negative association with old-age anxiety once actionable and protective digital competencies are accounted for. In contrast, practical know-how, positive financial attitude, and self-protection are more consistently associated with lower anxiety. Supplementary heterogeneity analyses suggest that the positive conditional association between financial knowledge and anxiety is most visible among men aged 50–59, although these subgroup patterns should be interpreted cautiously. These findings do not imply that financial knowledge is unimportant. Rather, they suggest that Big Three financial knowledge alone may be an insufficient proxy for the dimensions of financial capability associated with lower self-reported old-age anxiety in digital financial environments. Given the cross-sectional design, the findings are interpreted as conditional associations rather than causal effects.

Inflation expectations play an important role in monetary transmission, yet little is known about whether digital financial literacy (DFL) is associated with how individuals form such expectations across different forecasting horizons. This study examines the association between DFL and inflation expectations at the one-, three-, and five-year horizons using a large-scale online survey of more than 150,000 Japanese investors. DFL is measured as a multidimensional construct capturing digital and financial knowledge, awareness and use of digital financial services, financial attitudes and behaviors, and self-protection capabilities. Ordered probit models are employed to estimate the association between DFL and horizon-specific inflation expectations while controlling for demographic, socioeconomic, and behavioral characteristics. The results indicate a clear horizon-dependent pattern. Higher DFL is negatively associated with one-year-ahead inflation expectations but positively associated with inflation expectations at the three- and five-year horizons. Marginal-effects estimates indicate that higher DFL shifts the short-run distribution toward lower inflation categories, but shifts the medium- and long-run distributions toward higher inflation categories. These findings are consistent with the possibility that individuals with higher DFL process short-term and longer-term inflation-related information differently. However, because the analysis is based on cross-sectional observational data, the results should be interpreted as conditional associations rather than causal effects.

This study investigates the relationship between digital financial literacy (DFL) and hyperbolic discounting among 104,993 active securities account holders in Japan. As digital financial services expand rapidly, individuals increasingly require not only traditional financial knowledge but also the capacity to understand digital platforms, evaluate online financial information, and manage emerging technological risks. Using data from the 2025 wave of the Survey on Life and Money, hyperbolic discounting is measured through intertemporal monetary choice scenarios, while DFL is constructed as a multidimensional index encompassing digital knowledge, financial knowledge, service awareness, attitudes, behaviors, practical capability, and protection against digital fraud. Probit regression results reveal a statistically significant negative association between DFL and hyperbolic discounting, indicating that individuals with stronger digital financial competencies are less likely to exhibit hyperbolic discounting. Attitudinal components of DFL exhibit the strongest effects, suggesting that internalized financial beliefs may play a more decisive role than technical knowledge in promoting time-consistent decision-making. Subsample analyses further highlight gender-differentiated patterns in demographic and economic influences on present bias. These findings contribute to behavioral finance by integrating digital capability into intertemporal choice research and provide policy-relevant implications for designing comprehensive financial education and digital literacy initiatives in increasingly digitalized financial environments.

Investment in risky financial assets plays a crucial role in individual wealth accumulation and broader financial market development. However, existing research has primarily emphasized financial literacy while giving limited attention to behavioral mechanisms that may weaken its influence on investment behavior. In particular, hyperbolic discounting, reflecting time-inconsistent preferences that favor immediate rewards over long-term gains, may constrain the effective translation of financial knowledge into forward-looking financial decisions. Against this background, this study examines whether hyperbolic discounting mediates the association between financial literacy and investment in risky assets using large-scale survey data from Japan’s Money and Life survey. Employing regression-based mediation analysis within a cross-sectional framework, the results indicate that financial literacy is strongly and positively associated with risky asset investment, while hyperbolic discounting exerts a statistically significant but economically small mediating effect that slightly attenuates this relationship. The findings suggest that cognitive financial capability remains the dominant driver of participation in risky financial markets, whereas present-biased preferences play a secondary behavioral role. These results provide important implications for investors, educators, and policymakers by highlighting that policies aimed at improving financial literacy are likely to yield substantial investment benefits, while complementary interventions addressing behavioral biases may offer additional, though more modest, gains in promoting long-term, forward-looking financial decision-making.

Inflation expectations play a central role in monetary policy effectiveness, yet relatively little is known about how individual behavioral traits shape expectation formation. This study examines whether time discounting and hyperbolic discounting, key dimensions of intertemporal preferences, are systematically associated with household inflation expectations. Using large-scale survey data from Japan that elicit both time preference measures and qualitative inflation expectations, we analyze expectations over one-, three-, and five-year horizons. The empirical analysis employs ordered probit models that fit well with the categorical nature of survey-based inflation expectations and controls for a rich set of demographic, socioeconomic, and behavioral characteristics, including financial literacy and risk preferences. The results reveal clear horizon-dependent patterns. Hyperbolic discounting is positively associated with short-term inflation expectations, suggesting that present-biased individuals place greater weight on recent inflation developments. In contrast, higher time discount rates are associated with higher inflation expectations at medium and longer horizons, indicating that impatience is more relevant for beliefs about distant future prices. These findings provide novel evidence on the behavioral micro-foundations of inflation expectation formation and highlight the importance of heterogeneity in time preferences. From a policy perspective, the results suggest that one-size-fits-all communication strategies may be insufficient and that effective expectation management may require tailoring messages to account for differences in individuals’ time orientation across forecast horizons.