There is considerable evidence that health and development are better, on average, in countries with greater income equality. However, much of the research has focussed on average health and wellbeing; it is less clear how this benefit is distributed across society – do people from advantaged and disadvantaged socioeconomic backgrounds benefit equally? Further, there has been little research on the relationship between income inequality and child health.
This thesis aimed to explore how the social gradient in child health and development varies in relation to income inequality in high income countries.
I used two approaches to answer the question: Does everyone do better in more equal countries? I conducted a critical review of previous literature comparing social gradients in health and wellbeing. I also conducted original analysis using a comparative cohort study. I compared social gradients in health and development among children aged 4-6, using 7 cohort studies from 6 countries (US, UK, Australia, Canada, Netherlands, Sweden). I reviewed approaches to comparing data between studies and across countries, and harmonised the samples and variables to facilitate comparisons.
The studies in the critical review varied considerably, but there was substantial evidence that health and wellbeing are better for everyone in more equal countries (with the most disadvantaged benefitting the most). In the comparative cohort analysis, there was some evidence that social gradients are steeper in more equal countries (inequalities are greater), and some evidence that everyone does better. However, there were many inconsistencies and comparisons were challenging due to measurement differences between the cohorts.
The observation that social gradients are shallower in some countries than others shows that such inequalities can be prevented. There is growing evidence that people from all social backgrounds would benefit if countries had greater income equality.
