The Effect of Internet and Covid-19 on Mental Health

One in five people is affected by mental illness, the great majority suffering from depression or crippling anxiety. It is one of the main causes of the overall disease burden worldwide. Major depression is thought to be the second leading cause of disability worldwide and a major contributor to the burden of suicide and ischemic heart disease. The proportion of people affected has steadily increased . Whilst there is increasing research on how one's own mental health affects one's productivity, poverty and even physical health, not much is known about spill-overs onto other agents. The aim of this PhD is to fill this gap in the literature.

The objectives of this PhD are:
1. To examine whether and how one's own mental health affects his/her spouse
2. To investigate whether and how parental mental health affects his/her children mental health
3. To study potential school peer effects amongst children

It is difficult to identify the causal effects between the mental health of individual and others. As described by Manski (1993), the finding that individuals in the same area have similar outcomes is not sufficient to show that they influence each other. There are three main issues: the reflection problem, unobserved variables and common shocks, so I propose the following modifications to mitigate these issues. As contagious effect examines the marginal effect of other's mental health issue on one's utility (Clark and Oswald, 1998), I consider the mental health of a partner as an additional
input into a health production function (Grossman, 1972) and estimate the marginal product of partner's mental health. Following Clark and Etilé (2011), I introduce individual well-being scores and relate them to both own and partner's mental health.

The proposed research can generate potential academic impact in terms of high-quality academic publications in the area of health economics and public health. The causes of mental health problems and how conditions can be better understood through this study. It helps us to gain a sense of positive externalities that some mental health interventions may bring. Research results from this project can provide guidance to policymakers in order to design more effective preventions of mental illness. For example, couple therapy, as a supplementary or alternative therapy for individual treatment, might receive more attention. The findings of this study will also provide evidence to the society to promote better household and school environment for young children to avoid mental illness among the younger population.