This thesis aims to identify causal effects using a natural experimental approach. We focus on the Great Hanshin-Awaji Earthquake in midwestern Japan as a source of exogenous variation in the variables of interest. Chapter 1 explores the causal effect of schooling on juvenile delinquency using variation in schooling caused by policy interventions in specific municipalities after the earthquake. Using the instrumental variable estimator to address endogeneity problems arising from simultaneity and unobserved heterogeneity, we find that schooling reduces juvenile delinquency, although some of our estimates have large standard errors and are imprecisely estimated. The results indicate that a one-percentage-point increase in the high school participation rate reduces the number of juvenile arrests by approximately 1.1 per 1,000 youths. 1 Estimates of social benefits show that it is less expensive to reach a target level of social benefits by improving schooling than by strengthening police forces. Chapter 2 studies the causal effect of volunteer work on the mortality of the elderly. After the earthquake, levels of volunteering increased considerably in municipalities hit by the earthquake, while other municipalities did not experience such a sharp increase. This exogenous shift in levels of volunteering is exploited to address the endogeneity problem associated with estimating the effects of volunteering. Specifically, unobserved heterogeneity across municipalities that affects both morality and the level of volunteering, such as the quality of local health care services, may bias estimates on the effect of volunteering. The results indicate that volunteering has no significant effect on mortality amongst people in their 50s and 60s, while it significantly reduces mortality amongst people in their 70s and 80s or older. Evaluated at the mean, the estimate implies that the life of approximately one person aged 80 or older (out of 186 persons) is saved in a given year when the number of volunteers increases by 100 (out of 1,911 persons).

Psychiatric distress, smoking and excessive alcohol consumption are common health problems which often occur together and are patterned by socioeconomic position. Smoking and drinking behaviours and mental health problems tend to develop over the transition from adolescence to adulthood, so this thesis aimed to investigate the mechanisms by which socioeconomic factors influence their co-development during this stage of life as young people make transitions into adult social roles. Data were primarily taken from three UK cohort studies (two nationwide birth cohorts respectively born in 1958 and 1970, and a cohort of adolescents from Glasgow who were also born in the early 1970s), so it was possible to examine whether mechanisms were context-dependent. Additional data from the youth sub-sample of the British Household Panel Study allowed investigation of socioeconomic inequalities in early adolescent smoking development in more recent history (1994-2008). A combination of person and variable centred analysis techniques (latent class analysis, structural equation modelling, propensity weighting, and event history analysis) were employed to investigate the role of socioeconomic background and transitions to adulthood in development of smoking, drinking and psychiatric distress in adolescence and early adulthood. Inverse probability weighting and multiple imputation were employed to account for missing data. A strong association was identified between socioeconomic disadvantage and adolescent smoking, despite recent increases in tobacco control in the UK. Smoking appeared to be an important mechanism, or at least a marker for other mechanisms, linking socioeconomic disadvantage to heavier drinking, psychiatric distress, and early school-leaving. Aside from smoking, there were other mechanisms leading to heavy drinking and psychiatric distress. For psychiatric distress, these were still mainly associated with socioeconomic disadvantage, especially in early adulthood, whereas for drinking there were mechanisms associated with socioeconomic advantage. Participation in tertiary education appeared to be an important example of such a mechanism, linking socioeconomic advantage to heavier drinking in early adulthood. Remaining in education was strongly linked to delaying other adulthood transitions, but different patterns of early transitions exhibited different associations with smoking, drinking and distress in different contexts. Tackling inequalities in smoking may help reduce inequalities in drinking and distress in adolescence and early adulthood, and policies increasing access to tertiary education should consider the deleterious effects on drinking behaviours.

The thesis consists of three self-contained articles that empirically investigate socio-economic differences in, and interrelationships amongst, science knowledge, biomedical self-efficacy, and participation in medical decision-making. Chapter 2 investigates age-related bias in the science knowledge questions in the Wellcome Trust Monitor Survey Waves I and II. It also examines what evidence there is for three dimensions of knowledge. Chapter 3 studies the influence of Internet use and paying attention to medical stories online in reducing science knowledge and biomedical self-efficacy gaps between low and high educational groups. Wave II of the Wellcome Trust Monitor Surveys is employed in this chapter. Chapter 4 scrutinises the influence of various socio-economic factors, biomedical self-efficacy, and trust in physicians and other medical practitioners on public willingness and confidence to take part in the medical decision-making process. Chapter 4 uses Wave III of the Wellcome Trust Monitor Survey. Chapter 2 finds evidence for age-related bias in the science knowledge battery of questions; no evidence of a misinformed group of respondents was found; a group who consistently said they didn’t know instead of providing an answer that was wrong was found; a sensitivity analysis showed that using the summed score approach leads to the same substantive conclusions as a model taking into account age-related non-invariance. Chapter 3 finds evidence of education-based knowledge and efficacy gaps. It also finds some evidence that the Internet can help reduce that democratic deficit in information. Chapter 4 finds evidence that people are generally confident to participate. Those who are more self-efficacious are also more confident to participate in medical decisions. The opposite held true for those who place high trust in doctors. Women were found to be more confident than men.

Social Capital is considered an important asset for development, both at local and higher levels, and has been explored across the social sciences for decades. Attempts to define and measure it in increasingly precise ways continue in order to place it at the centre of policymaking. Indeed, it is considered a precious capital in times where resources are becoming scarce. This thesis investigates the dimensions of social capital and estimates them at small area level for England and Wales in 2011. The first step is the identification of three factors measuring membership, citizenship and politics and neighbourliness dimensions using survey data and a Confirmatory Factor Analysis. The second step is to test the hypothesis that other individual characteristics and geographical characteristics may influence levels of these factors. Complex Multilevel models with individual covariates and area-level covariates from the Census and administrative sources confirm the hypothesis: the factors depend on age, gender, ethnicity, religion, marital status, socio-economic class, employment, state of health and education at individual level and ethnic diversity and economic profile at area level. Lastly, Multilevel Model results have been used as a starting point for the final synthetic estimates at small area for all the Middle Super Output Areas of the average levels of the three factors. While Membership and Citizenship and Politics social capital show higher differentials, Neighbourliness seems to be more spread and, on average, higher than the other two factors across the two countries.