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Essays on policy evaluation: assessing policy impact on mental well-being among vulnerable populations using quasi-experimental methods

Mu, Yi (2022). Essays on policy evaluation: assessing policy impact on mental well-being among vulnerable populations using quasi-experimental methods. (Unpublished Doctoral thesis, City, University of London)


This thesis investigates the impact of policies on people’s mental and physical wellbeing. It highlights the impact on vulnerable people and explores the heterogeneity of impacts for those from different backgrounds.

Chapter 1 explores the impact of displacement due to land expropriation on physical and mental health using data on household heads and their spouses from the Longitudinal Survey on Rural Urban Migration in China. The results show that the displaced are more likely to be sick or injured and have higher medical expenditure. At the same time, impacts on the standardised mental health factor and self-rated health status are statistically insignificant. This chapter investigates this further using the time since displacement and finds that the impact on mental health is significantly negative for the recently displaced people, while the impact on physical health is significantly negative for the long-term displaced. In order to understand these results, this chapter also explores effects on other outcomes and finds that displaced people have more years of education, fewer children and are less likely to have medical insurance. Those having more years of education are more likely to care about their health and thus spend more on it. Having fewer or no children can explain the higher possibility of being sick or injured. People without a settled family life are more prone to dangerous jobs and unstable lifestyles.

Chapter 2 explores the heterogeneous impacts of forced displacement due to the Three Gorges Dam project (TGDP) on people’s mental well-being in China. Using the TGDP survey data on both residents and relocatees, this chapter estimates the average treatment effect on the treated and finds that depression levels increased among the displaced. The impacts for other standardised mental health factors, including anxiety, low mood and low self-esteem, are statistically insignificant. This chapter also finds heterogeneous impacts on mental health considering differences in people’s educational level, marital status, moving distance and whether they were displaced individually or with their village. The illiterate individuals became more anxious than those having general education. The divorced were not as severely affected as the married for depression and low mood but were worse for anxiety and low self-esteem. People who moved out of town became much more depressed than those who moved within the town. Finally, people who moved with the village became more depressed than those who moved with their households alone. These results suggest that heterogeneity of the impacts exists, and thus it should be considered when making policy decisions.

With an event study approach, Chapter 3 explores the dynamics of the heterogeneous impact of lifting shielding by ethnicity for the clinically extremely vulnerable people in the COVID-19 pandemic. There is no evidence suggesting that the high-risk individuals from a BAME background were more likely to have COVID-19 symptoms once the shielding requirement was relaxed than those from a non-BAME background. However, the impact on the diagnosis of mental ill-health is significantly higher for the high-risk BAME than their non-BAME counterparts after the shielding was relaxed in July 2020. Furthermore, they felt more at risk of catching COVID-19 in November 2020 when the daily infections increased, and the shielding was not required. This negative impact continued in January 2021, when the shielding requirement was reimplemented. In terms of behaviour, when the COVID-19 pandemic deteriorated in November 2020, its impact on the use of trains by the high-risk BAME decreased significantly, showing that the high-risk BAME population were more concerned about catching the virus than the high-risk non-BAME population. This could explain the insignificant difference between high-risk BAME and non-BAME in having COVID-19 symptoms; that is, although the high-risk BAME may live in an environment that increases the chance of getting infected than the high-risk non-BAME, their cautiousness lowered their exposure to the virus.

Publication Type: Thesis (Doctoral)
Subjects: B Philosophy. Psychology. Religion > BF Psychology
H Social Sciences > HB Economic Theory
H Social Sciences > HT Communities. Classes. Races
Departments: School of Policy & Global Affairs > Economics
School of Policy & Global Affairs > School of Policy & Global Affairs Doctoral Theses
Doctoral Theses
[thumbnail of Mu thesis 2022 redacted.pdf] Text - Accepted Version
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