An exploratory multilevel analysis of income,income inequality and self-rated health of the elderly in China

In the last three decades, China has experienced rapid economic development and growing economic inequality, such that economic disparities between rural and urban areas, as well as coastal and interior areas have deepened. Since the late 1990s China has also experienced an ageing population which has attracted attention to the wellbeing of the rapidly growing number of elderly. This research aims to characterise province differences in health and to explore the effects of individual income and economic disparity in the form of income inequality on health outcomes of the elderly. The study is based on the Chinese Longitudinal Healthy Longevity Survey data collected in 2008 for 23 provinces. Multilevel logistic models are employed to investigate the relationship between income, income inequality and self-rated health for the elderly using both individual and province-level variables. Results are presented as relative odds ratios, and for province differentials as Median Odds Ratios. The analysis is deliberately exploratory so as to find evidence of income effects if they exist and particular attention is placed on how province-level inequality (contemporaneous and lagged) may moderate individual relationships. The results show that the health of the elderly is not only affected by individual income (the odds of poor health are 3 times greater for the elderly with the lowest income compared to those at the upper quartile) but also by a small main effect for province-level income inequality (odds ratio of 1.019). There are significant cross-level interactions such that where inequality is high there are greater differences between those with and without formal education, and between men and women with the latter experiencing poorer health.     

Income inequality and self-rated health in Stockholm, Sweden: a test of the 'income inequality hypothesis' on two levels of aggregation

The number of studies analysing income inequality and health are voluminous. However, when empirically testing the income inequality hypothesis, the level of aggregation could be crucial for whether we find an association or not and for the mechanisms we believe are active. This study hence investigates: (1) the two-year lagged effect by income inequality on health at two levels of aggregation; municipalities and neighbourhoods in Sweden; (2) whether spending on social goods accounts for the association between income inequality and health; (3) the effect by income inequality among the affluent and the disadvantaged in municipalities and neighbourhoods, respectively. The empirical data is based on a Swedish public health survey in 2002 and includes residents of Stockholm aged 18-84 years. The sample consists of 28,092 individuals nested within 22 municipalities and 709 neighbourhoods in the county of Stockholm with a non-response rate of 37 percent. A total population register (HSIA) is further used for the construction of contextual-level indicators. Primary method used is multi-level logistic regression. The findings indicate a moderate effect by high and very high income inequality on self-rated poor health at the municipality-level. The association, however, ceases after adjustment for spending on social goods. No detrimental effect by income inequality on self-rated health at the neighbourhood-level is found. The results further suggest that poor individuals residing in high inequality neighbourhoods do not have poorer health than those residing in low inequality contexts while high inequality is most deleterious for poor individuals at the municipality-level. In sum, the findings suggest that reduced spending on social goods could account for the association between income inequality and health at the municipality-level. The contrasting findings at the neighbourhood- and municipality-level indicate that it is important to consider the level of aggregation when studying health effects by income inequality.     

Income inequality and self-rated health in US metropolitan areas: A multi-level analysis

Income inequality has been found to affect health in a number of international and cross-national studies. Using data from a telephone survey of adults in the United States, this study analyzed the effect of metropolitan level income inequality on self-rated health. It combined individual data from the 2000 Behavioral Risk Factor Surveillance System with metropolitan level income data from the 2000 Census. After controlling for smoking, age, education, Black race, Hispanic ethnicity, sex, household income, and metropolitan area per capita income, this study found that for each 1 point rise in the GINI index (on a hundred point scale) the risk of reporting Fair or Poor self-rated health increased by 4.0% (95% confidence interval 1.6–6.5%). Given that self-rated health is a good predictor of morbidity and mortality, this suggests that metropolitan area income inequality is affecting the health of US adults.     

Income inequality,area-level poverty,perceived aversion to inequality,and self-rated health in Japan

In this study we conduct a multilevel analysis to investigate the association between regional income inequality and self-rated health in Japan, based on two nationwide surveys. We confirm that there is a significant association between area-level income inequality and individual-level health assessment. We also find that health assessment tends to be more sensitive to income inequality among lower income individuals, and to degree of area-level poverty, than income inequality for the society as a whole. In addition, we examine how individuals are averse to inequality, based on the observed association between inequality and self-rated health.     

Multilevel analysis of income, income inequalities and health in Spain

The aim of this study is to test the influence of personal income (absolute income hypothesis), income inequalities and welfare (relative income hypothesis) on health. A multilevel cross-sectional logit model is used with two alternative specifications of the dependent variable: self-perceived health and chronic illnesses, and six specifications of the income inequality: three positive and three normative. This study incorporates lagged values of the regional variables and interactions between the individual and the regional variables. The data is drawn from the Spanish Life Conditions Survey for 2007 and consists of 28,023 individuals over 16 from 17 autonomous communities. The results support the absolute income hypothesis that a higher level of personal income is correlated with a lower probability of negative health outcomes. The relative income hypothesis results are mixed with only some indicators showing a significant relationship with health. The results also indicate that being a man, being married, working and having a high level of education are related to improved health. This study emphasizes the importance both of the health variable and of the specification of income inequality, and contributes to augmenting the limited empirical evidence available in Spain on the influence of income and income inequalities on the health of the population.     

Income inequality,perceived happiness,and self-rated health: Evidence from nationwide surveys in Japan

In this study, we examined how regional inequality is associated with perceived happiness and self-rated health at an individual level by using micro-data from nationwide surveys in Japan. We estimated the bivariate ordered probit models to explore the associations between regional inequality and two subjective outcomes, and evaluated effect modification to their sensitivities to regional inequality using the categories of key individual attributes. We found that individuals who live in areas of high inequality tend to report themselves as both unhappy and unhealthy, even after controlling for various individual and regional characteristics and taking into account the correlation between the two subjective outcomes. Gender, age, educational attainment, income, occupational status, and political views modify the associations of regional inequality with the subjective assessments of happiness and health. Notably, those with an unstable occupational status are most affected by inequality when assessing both perceived happiness and health.     

Ecological analysis of the health effects of income inequality in Argentina

OBJECTIVES: Despite a large body of empirical literature, a consensus has not been reached concerning the health effects of income inequality. This study contributes to ongoing debates by examining the robustness of the income inequality-population health relationship in Argentina, using five different income inequality indexes (each sensitive to inequalities in differing parts of the income spectrum) and five measures of population health. STUDY DESIGN: Cross-sectional, ecological study. METHODS: Income and self-reported morbidity data from Argentina's 2001 Encuesta de Condiciones de Vida (Survey of living conditions) were analysed at the provincial level. Provincial rates of male/female life expectancy and infant mortality were drawn from the Instituto Nacional de Estadistica y Censos database. RESULTS: Life expectancy was correlated in the expected direction with provincial-level income inequality (operationalized as the Gini coefficient) for both males (r=-0.55, P<0.01) and females (r=-0.61, P<0.01), but this association was not robust for all five income inequality indexes. In contrast, infant mortality, self-reported poor health and self-reported activity limitation were not correlated with any of the income inequality indexes. CONCLUSIONS: This study adds further complexity to the literature on the health effects of income inequality by highlighting the important effects of operational definitions. Mortality and morbidity data cannot be used as reasonably interchangeable variables (a common practice in this literature), and the choice of income inequality indicator may influence the results.     

Social capital,income inequality and self-rated health in Chita peninsula,Japan: a multilevel analysis of older people in 25 communities

The effect of social capital on one's health has drawn researchers' attention. In East-Asian countries, however, such an effect has been less studied than in Western countries. Mindful of this background, this study aimed to investigate the linkage between social capital and health at the level of a small area in Japan, and also to examine whether social capital mediates the relation between income inequality and health.     

Global variations in health: Evaluating Wilkinson's income inequality hypothesis using the World Values Survey

This international comparative study analyses individual-level data derived from the World Values Survey to evaluate Wilkinson's [(1996). Unhealthy societies: The afflictions of inequality. London: Routledge; (1998). Mortality and distribution of income. Low relative income affects mortality [letter; comment]. British Medical Journal, 316, 1611–1612] income inequality hypothesis regarding variations in health status. Random-coefficient, multilevel modelling provides a direct test of Wilkinson's hypothesis using micro-data on individuals and macro-data on income inequalities analysed simultaneously. This overcomes the ecological fallacy that has troubled previous research into links between individual self-rated health, individual income, country income and income inequality data. Logic regression analysis reveals that there are substantial differences between countries in self-rated health after taking account of age and gender, and individual income has a clear effect in that poorer people report experiencing worse health. The Wilkinson hypothesis is not supported, however, since there is no significant relationship between health and income inequality when individual factors are taken into account. Substantial differences between countries remain even after taking account of micro- and macro-variables; in particular the former communist countries report high levels of poor health.     

A multilevel analysis of social capital and self-rated health: Evidence from China

We investigate relationship between social capital and self-rated health (SRH) in urban and rural China. Using a nationally representative data collected in 2005, we performed multilevel analyses. The social capital indicators include bonding trust, bridging trust, social participation and Chinese Communist Party membership. Results showed that only trust was beneficial for SRH in China. Bonding trust mainly promoted SRH at individual level and bridging trust mainly at county level. Moreover, the individual-level bridging trust was only positively associated with SRH of urban residents, which mirrored the urban–rural dual structure in China. We also found a cross-level interaction effect of bonding trust in urban area. In a county with high level of bonding trust, high-bonding-trust individuals obtained more health benefit than others; in a county with low level of bonding trust, the situation was the opposite.     

Income inequality, social capital and self-rated health and dental status in older Japanese

The erosion of social capital in more unequal societies is one mechanism for the association between income inequality and health. However, there are relatively few multi-level studies on the relation between income inequality, social capital and health outcomes. Existing studies have not used different types of health outcomes, such as dental status, a life-course measure of dental disease reflecting physical function in older adults, and self-rated health, which reflects current health status. The objective of this study was to assess whether individual and community social capital attenuated the associations between income inequality and two disparate health outcomes, self-rated health and dental status in Japan. Self-administered questionnaires were mailed to subjects in an ongoing Japanese prospective cohort study, the Aichi Gerontological Evaluation Study Project in 2003. Responses in Aichi, Japan, obtained from 5715 subjects and 3451 were included in the final analysis. The Gini coefficient was used as a measure of income inequality. Trust and volunteering were used as cognitive and structural individual-level social capital measures. Rates of subjects reporting mistrust and non-volunteering in each local district were used as cognitive and structural community-level social capital variables respectively. The covariates were sex, age, marital status, education, individual- and community-level equivalent income and smoking status. Dichotomized responses of self-rated health and number of remaining teeth were used as outcomes in multi-level logistic regression models. Income inequality was significantly associated with poor dental status and marginally significantly associated with poor self-rated health. Community-level structural social capital attenuated the covariate-adjusted odds ratio of income inequality for self-rated health by 16% whereas the association between income inequality and dental status was not substantially changed by any social capital variables. Social capital partially accounted for the association between income inequality and self-rated health but did not affect the strong association of income inequality and dental status.     

Social capital, income inequality, and self-rated health in 45 countries

There has been growing interest in the relationship between the social environment and health. Among the concepts that have emerged over the past decade to examine this relationship are socio-economic inequality and social capital. Using data from the World Values Survey and the World Bank, we tested the hypothesis that self-rated health is affected by social capital and income inequality cross-nationally. The merit of our approach was that we used multilevel methods in a larger and more diverse sample of countries than used previously. Our results indicated that, for a large number of diverse countries, commonly used measures of social capital and income inequality had strong compositional effects on self-rated health, but inconsistent contextual effects, depending on the countries included. Cross-level interactions suggested that contextual measures can moderate the effect of compositional measures on self-rated health. Sensitivity tests indicated that effects varied in different subsets of countries. Future research should examine country-specific characteristics, such as differences in cultural values or norms, which may influence the relationships between social capital, income inequality, and health.     

An investigation of the longitudinal relationship between neighbourhood income inequality and individual self-rated health in England

There are mixed findings on whether neighbourhood income inequality leads to better self-rated health (SRH) or not. This study considers two hypotheses: individuals living in more unequal neighbourhoods have better SRH and the level of neighbourhood income inequality and its impact on SRH is moderated by household and neighbourhood level income related variables. Data from Waves 8–10 of the UK Household Longitudinal Study for respondents living in England at wave 8 were used. Neighbourhood income inequality was measured using Gini coefficients of household income from the Pay As You Earn and benefits systems for Lower Super Output Areas. Longitudinal ordinal multilevel models predicted self-rated health in 2016–18, 2017–19 and 2019-20 by income inequality and its interaction with household income, neighbourhood median income and neighbourhood deprivation, conditional on individual educational attainment, age, sex, ethnic group, years lived in current residence, region of residence and study wave. There were 24,889 respondents analysed over three waves. SRH was worse for those living in more income equal neighbourhoods. There was no indication that neighbourhood inequality was moderated by household income, neighbourhood median income or neighbourhood deprivation. These findings are in line with the balance of existing evidence and support policy interventions that aim to create mixed communities for the purpose of improving population health.     

Relative income inequality and selected health outcomes in urban Chinese youth

Self reported cross-sectional data gathered in 2002 from 12,449 middle and high school students from seven major cities in China were examined to explore the association of self-perceived relative income inequality (SPRII) with general health status, depression, stress, and cigarette smoking. Two types of self-perceived relative income were evaluated: household income relative to peers (SPRII-S) and relative to their own past (SPRII-P). SPRII-S and SPRII-P were coded as three-level categorical variables: lower, equal, and higher. As hypothesized, the youth in the “Lower” SPRII-S or SPRII-P groups reported the worst general health and the highest levels of depression and stress; the youth in the “Higher” groups reported the best general health. Unexpectedly, the youth in the “Higher” groups did not report the lowest levels of depression and stress, and the relationship between SPRII and cigarette smoking was even less straightforward. The expected positive relationship between SPRII and the general health status is consistent with previous research, but the relationships between SPRII and depression, stress, and cigarette smoking behavior are not. Further studies are needed to elucidate the complex associations between SPRII and health outcomes in rapidly transforming economies such as China.     

Beefing up with the Chans: evidence for the effects of relative income and income inequality on health from the China Health and Nutrition Survey

A great deal of research has examined the hypothesis that the well-being of individuals is shaped not just by the absolute level of resources available to them but also the level of resources available to them relative to others in their cohort or community. Several causal pathways have been hypothesized to explain associations between relative social position and health. For example, greater community income could increase the overall availability of health care in a community or decrease the availability for people for any given level of individual income. Relative social position could also create stress, resulting in adverse health outcomes through increased hypertension and other pathways. We explore yet another pathway by which relative social position may affect health. Specifically, to the extent that norms about physical appearance might be shaped by one's observations of others, we examine whether obesity might constitute another physiologic pathway by which community attributes could influence aspects of individual health, such as hypertension. We examine this hypothesis in rural China, where income often limits food intake so that, if community norms are an important determinant of individual obesity, higher community income could increase the obesity rate in a community and therefore change norms about obesity. These norms, in turn, could increase individuals' chances of being obese given their income. To test this hypothesis, we use multilevel linear probability models to examine the relationship between ecologic factors, i.e., relative income and income inequality, and health risk factors, i.e., obesity and hypertension among a sample of Chinese adults interviewed in four waves over 9 years. The results suggest that, among rural Chinese residents, increasing community average income and income inequality are positively associated with both obesity and hypertension. However, the effect of relative income on hypertension is not accounted for by increases in obesity. We did not find a strong relationship between socioeconomic conditions and the health risk factors among urban residents, where norms might be likely to be less strongly influenced by local attributes. Hence, the present study provides evidence supporting the hypothesis that relative income and income inequality affect obesity and hypertension, but no evidence that the effects on hypertension operated through effects on obesity.     

The neighborhood context of relative position, trust, and self-rated health

The relative position hypothesis proposes that an individual's relative position in a community or population influences their health because (1) unfavorable comparisons lead those with a lower position to experience negative emotions that cause stress and detrimentally impact health and well-being, and (2) individuals with different statuses are less likely to develop trust and cohesion with one another. These processes are important for individual health and also because their results may detract from community level social resources. Surprisingly little work has investigated this hypothesis within small units of analysis such as neighborhoods. In this research, logistic regression analyses were conducted on data from the Los Angeles Family and Neighborhood Survey to test the relative position hypothesis as it applies to distrust of neighbors and fair or poor self-rated health, and whether the relationship varies across neighborhood income inequality. Results indicate that relative position significantly predicts distrust, such that those with higher local position are more likely to distrust their comparatively lower income neighbors. Relative position was not significantly associated with self-rated health, but lack of trust of neighbors was significantly and positively associated with below average self-rated health. The effect of relative position did not vary across neighborhood income inequality for either outcome. Implications for theories of income inequality and health are discussed.     

Change in income and change in self-rated health: Systematic review of studies using repeated measures to control for confounding bias

It is generally assumed that income is strongly and positively associated with health. However, much of the evidence supporting this assumption comes from cross-sectional data or analyses that have not fully accounted for biases from confounding and health selection (the reverse pathway from health to income). This paper reports results of a systematic review of panel and longitudinal studies investigating whether changes in income led to changes in self-rated health (SRH) in adults. A variety of electronic databases were searched, up until January 2010, and thirteen studies were included, using data from five different panel or longitudinal studies. The majority of studies found a small, positive and statistically significant association of income with SRH, which was much reduced after controlling for unmeasured confounders and/or health selection. Residual bias, particularly from measurement error, probably reduced this association to the null. Most studies investigated short-term associations between income and SRH or the effect of temporary (usually one year) income changes or shocks, so did not rule out possibly stronger associations between health and longer-term average income or income lagged over longer time periods. Nevertheless, the true causal short-term relationship between income and health, estimated by longitudinal studies of income change and SRH that control for confounding, may be much smaller than that suggested by previous, mostly cross-sectional, research.     

我国居民与收入相关的健康不平等实证研究

本文利用中国健康与营养调查（CHNS）2006年的调查数据，从定量的角度对我国居民与收入相关的健康不平等进行了分析。本文利用有序Probit模型获得了自评健康数据背后的实际健康得分，在此基础上计算健康集中指数衡量我国居民与收入相关的健康不平等程度。结果表明，我国居民的健康不平等问题较为严重，健康不平等问题在城乡之间和不同经济发展水平地区之间存在着较大的差别。     

Healthcare investment and income inequality

This paper examines how the relative shares of public and private health expenditures impact income inequality. We study a two period overlapping generation's growth model in which longevity is determined by both private and public health expenditure and human capital is the engine of growth. Increased investment in health, reduces mortality, raises return to education and affects income inequality. In such a framework we show that the cross-section earnings inequality is non-decreasing in the private share of health expenditure.We test this prediction empirically using a variable that proxies for the relative intensity of investments (private versus public) using vaccination data from the National Sample Survey Organization for 76 regions in India in the year 1986–87. We link this with region-specific expenditure inequality data for the period 1987–2012. Our empirical findings, though focused on a specific health investment (vaccines), suggest that an increase in the share of the privately provided health care results in higher inequality.