The income inequality hypothesis rejected?

Economic growth, income inequality and life expectancy in China

China had made dramatic health gains before its economic reform that began in 1978 produced rapid economic growth in the ensuing years. Since the economic reform, China's income inequality has substantially increased, and health gains have stagnated. This article investigates the extent to which China's health stagnation may be attributable to the rise in income inequality in China. By simulating the improvement in life expectancy that could have resulted if, ceteris paribus, income inequality had stayed constant at the lowest level after the founding of the People's Republic of China in 1949, we find that the sharply increasing income inequality in China has contributed to life loss in China's population, about 0.6 years for men and 0.4 years for women. These findings suggest that redistribution of income from rich to poor may be one of the most important policy levers for improving population health in China.

Effects of the high-inequality of income on the breast cancer mortality in Brazil

As well as breast cancer mortality, the income inequality in Brazil is different between Federative units, including between units of the same region. To assess the effects of the high-inequality of income on breast cancer mortality in Brazilian Federative Units, in the 2010 year. This is an ecologic study. Deaths from breast cancer in Brazilian women according to Federative units were obtained from the Department of Informatics of the Unified Health System. Mortality by breast cancer was estimated per 100,000 women and age-standardized by the direct method according to World Health Organization population. Income inequality was measured by the Gini index obtained from the United Nations Development Programme. The High-inequality of income was classified by the third tercile of the distribution from the Gini index of the Federative units. Univariate analysis was performed according to data normality. Linear regressions were performed by the stepwise backward method. The confidence level was 5%. Stata® (Stata Corp, LC) 11.0. was used. The High-inequality of income was associated with worse social and demographic indicators. The age-standardized breast cancer mortality was larger in the high-inequality of income Federative units. In the adjusted analysis, these Federative units presented a mean of 2 more deaths (ranging from the 0.4 to 3.7 deaths, r² = 0.79; p = 0.018) by breast cancer per 100,000 women when compared to the Federative units without high-inequality of income. In the Brazilian Federative units, the high-inequality of income was associated with age-standardized breast cancer mortality more.

Decreasing income inequality and adolescent emotional distress: a population-based case study of Icelandic adolescents 2006-2016

OBJECTIVES

In this study, we aim to test whether changes in community income inequality influence adolescent emotional distress. We take advantage of the unique combination of data and history available in Iceland. This affluent welfare society has experienced extreme shifts in income inequality, allowing us to test whether changes in community income inequality are related to changes in adolescent emotional distress.

METHODS

Combining adolescent survey data (n = 24,107) with tax registry data on 76 neighborhood communities, we used a multilevel approach to model the data as longitudinal in order to test whether changes in community income inequality are related to changes in symptoms of anxiety and depression among adolescents.

RESULTS

The results showed that, after adjusting for relevant individual and community covariates, decreases in community income inequality were associated with decreases in symptoms of anxiety among adolescents (b = - 0.367, p ≤ 0.001), but not with decreases in symptoms of depression.

CONCLUSIONS

While the results provide a partial support for the income inequality thesis, we call for replications from other cultures and studies exploring the mediating role of social psychological processes.

Framing the tax and health nexus: a neglected aspect of public health concern

Previous studies have described various associations between tax policy and health. Here we propose a unifying conceptual framework of 'Five R's' to stimulate awareness about the importance of tax to health improvement. First, tax can improve representation and democratic accountability, and help make governments more responsive to the needs of its citizens. Second, tax can create a revenue stream for a universal pool of public finance for health care and other public services. Third, progressive taxation when combined with appropriate public spending can help redistribute wealth and income and mitigate social and health inequalities. Fourth, the re-pricing of harmful products (e.g. tobacco, alcohol and unhealthy food) can help reduce their consumption. Fifth, taxation provides a route by which certain harmful industries can be regulated. The paper also discusses the barriers that hinder the full potential for taxation to be used to improve health, including: weak tax administrations, large 'shadow economies', international trade liberalisation, tax avoidance, transfer pricing by transnational corporations and banking secrecy. We suggest that a greater awareness of the manifold associations between tax and health will encourage health practitioners to actively promote fairer and better taxation, thereby helping to improve health and reduce health inequalities.

The impact of increasing income inequalities on educational inequalities in mortality - An analysis of six European countries

Background

Over the past decades, both health inequalities and income inequalities have been increasing in many European countries, but it is unknown whether and how these trends are related. We test the hypothesis that trends in health inequalities and trends in income inequalities are related, i.e. that countries with a stronger increase in income inequalities have also experienced a stronger increase in health inequalities.

Methods

We collected trend data on all-cause and cause-specific mortality, as well as on the household income of people aged 35–79, for Belgium, Denmark, England & Wales, France, Slovenia, and Switzerland. We calculated absolute and relative differences in mortality and income between low- and high-educated people for several time points in the 1990s and 2000s. We used fixed-effects panel regression models to see if changes in income inequality predicted changes in mortality inequality.

Results

The general trend in income inequality between high- and low-educated people in the six countries is increasing, while the mortality differences between educational groups show diverse trends, with absolute differences mostly decreasing and relative differences increasing in some countries but not in others. We found no association between trends in income inequalities and trends in inequalities in all-cause mortality, and trends in mortality inequalities did not improve when adjusted for rising income inequalities. This result held for absolute as well as for relative inequalities. A cause-specific analysis revealed some association between income inequality and mortality inequality for deaths from external causes, and to some extent also from cardiovascular diseases, but without statistical significance.

Conclusions

We find no support for the hypothesis that increasing income inequality explains increasing health inequalities. Possible explanations are that other factors are more important mediators of the effect of education on health, or more simply that income is not an important determinant of mortality in this European context of high-income countries. This study contributes to the discussion on income inequality as entry point to tackle health inequalities. More research is needed to test the common and plausible assumption that increasing income inequality leads to more health inequality, and that one needs to act against the former to avoid the latter.

Electronic supplementary material

The online version of this article (doi:10.1186/s12939-016-0390-0) contains supplementary material, which is available to authorized users.