- PublicationEssays on Relationship between Physical Health and Mental Health : Panel Data AnalysisThere is a substantial gap in the literature about the effect of mental health on physical health. In two empirical chapters, this dissertation aims to understand how mental health influent physical health using a dynamic panel model and explore alternative explanations for this relationship using mediation analysis. In the first empirical chapter I investigate the relationship between physical health and mental health while accounting for the dynamics of physical health. I find that better past mental health positively influences present physical health. Better past physical health is also shown to have a positive impact on present physical health. Estimation by subgroups shows heterogeneous effects across age groups but no differences between males and females. In the second empirical chapter I propose and test a mediation framework for the analysis of the causal pathways through which mental health and overall life satisfaction on physical health. I find the significant mediator is an only physical activity and show that the indirect effect of past overall life satisfaction and mental health on physical health are strongly mediated by physical activity.My results suggest that both past mental health and past physical health can be powerful tools in promoting better present physical health. Mediation analysis shows that well-being provides influence both directly to physical health and indirectly via physical activity to better physical health.
- PublicationEssays on Minimum Wages and Labor Income Distribution in Thai Labor Market(University of the Thai Chamber of Commerce, 2020)
; ;Weerachart KilenthongUniversity of the Thai Chamber of Commerce. International CollegeThis dissertation provides two analyses aiming to examine the recent changes in the Thai labor market. The first analysis investigates the distributional change of the real hourly labor income in the Thai labor market from 1985 to 2017. The results show that overall labor income increased over the past three decades. The gender earnings gap was substantially reduced; however, the disparity between regions still exists. The results also indicate an increase in labor income of workers with primary school and higher education during the past three decades. This study found that an increase in labor income of primary school workers is associated with an increase in minimum wage while an increase in labor income of higher education workers is associated with an increase in labor demand. A future study should investigate the causal relationship between changes in labor income and its determinants for different workers to draw a more comprehensive conclusion. The second analysis evaluates the effects of minimum wages on various types of changes in labor market outcomes, including employment, dis-employment, labor force participation, weekly working hours, real hourly wages, real hourly total labor income, and various other types of income. The key contribution of this study is to use the individual-level panel data, i.e., the Matched-Outgoing Rotation Group (Matched-ORG) generated from the Thai Labor Force Survey. The results indicate that minimum wages harm employment, but the effects are relatively small, where the elasticities are in the range of - 0.0029 to -0.0474. However, the results show substantial and significant dis-employment effects for foreign workers, where the coefficients are in the range of 3.454 to 3.636. To reconcile two seemingly contradictory results, the study also estimates the effect of minimum wages on labor force participation and finds that an increase in labor force participation of Thai workers helps mitigate the disemployment for overall workers. The results also suggest that firms adjust working hours and reduce various types of other income to mitigate minimum wage shock. The study concludes that the competitive equilibrium theory can reasonably explain the effects of minimum wages on employment as well as the overall changes in the Thai labor market from 2002 to 2013. 72 278
- PublicationEquity Premium Puzzle and The Long-Run Risk Model : An Evidence from Stock Exchange of Thailand(University of the Thai Chamber of Commerce, 2020)
;University of the Thai Chamber of Commerce. International CollegeThis dissertation consist of two main parts. The first part empirically studies the standard consumption-based asset pricing model of Lucas (1978), Breeden (1979) and the consumption-based asset pricing model with recursive utility of Weil (1989) using quarterly data from Thailand from 2000 to 2016. The equity premium is calculated using FEDR returns, which includes dividend and right benefits and considers the effect of stock split. The key advantage of FEDR returns over the SET total returns is that the former returns are available since April 1975 while the latter is available only after January 2002. The result confirms that the models, which are the stan-dard consumption-based asset pricing model of Lucas (1978), Breeden (1979) and the consumption-based asset pricing model with the recursive utility of Weil (1989), assuming consumption growth are iid and Markov processes, cannot explain observed expected equity premium and observed expected risk-free return in Thailand data. Thailand's quarterly financial data from 2000 to 2016 exhibit the equity premium and risk-free rate puzzles. The second part shows that the long-run risk model (Bansal and Yaron, 2004) can solve the equity premium puzzle and risk-free rate puzzle in Thailand based on the data between 2000-2016. The calibration result gives a plau-sible value of risk-aversion which is less than 3 and a plausible value of elasticity of intertemporal substitution which is in a range between 1 and 2. In addition, the generalized method of moments (GMM) estimation results confirm that consump-tion growth and dividend growth are long-run processes, driven by a persistent latent variable and time-varying economic uncertainty. These together suggest that news about consumption growth and volatility have significant impact on asset prices. In addition, robustness checks for all models are performed using a diagnostic test, called Hansen-Jagannathan bound. 46 138
- PublicationImpacts of Early Childhood Investment on Child Development : An Evidence from Rural Thailand(University of the Thai Chamber of Commerce, 2020)
;University of the Thai Chamber of Commerce. International CollegeThis study estimates a production function of human capital at the early stage using various classes of inputs, including prior child's skills, parental material and time investments, household wealth, and an early childhood education intervention using data from the RIECE Thailand project. The first part of this study focuses only on the short-term impact of an early childhood education intervention. The results, based on an instrumental variable approach, show that an early childhood education intervention in rural Thailand has a significant short-term impact on child development, including gross motor, fine motor, expressive language, and personal and social skills. A reduced-form estimation using the randomization of additional teachers as a key explanatory variable, gives similar but smaller estimates relative to the one that uses the randomization as an instrument. The results are robust to various estimation methods, child development measures, and sample selections. In addition, we found that the impact of the new curriculum is quite homogeneous across sub-groups except in some dimensions, notably parental absence, main caregiver's working memory, mother's age, and teacher's job status. The second part extends the first one by estimating a production function of child development with more classes of inputs, including prior child's skills, parental material and time investments, and household wealth at the baseline. The results indicate that the new curriculum still has a significant impact on child development in all five domains while an increase of material and time investment boosts child development on expressive language domain only. The stock of child's skill at the baseline and household wealth have no significant impact on later developmental outcomes of the child. The results are robust to various estimation methods, child development measures, and sample selections. 64 224