Individual wealth rank, community wealth inequality, and self-reported adult poor health: a test of hypotheses with panel data (2002-2006) from native Amazonians, Bolivia

Growing evidence suggests that economic inequality in a community harms the health of a person. Using panel data from a small-scale, preindustrial rural society, we test whether individual wealth rank and village wealth inequality affects self-reported poor health in a foraging-farming native Amazonian society. A person's wealth rank was negatively but weakly associated with self-reported morbidity. Each step up/year in the village wealth hierarchy reduced total self-reported days ill by 0.4 percent. The Gini coefficient of village wealth inequality bore a positive association with self-reported poor health that was large in size, but not statistically significant. We found small village wealth inequality, and evidence that individual economic rank did not change. The modest effects may have to do with having used subjective rather than objective measures of health, having small village wealth inequality, and with the possibly true modest effect of a person's wealth rank on health in a small-scale, kin-based society. Finally, we also found that an increase in mean individual wealth by village was related to worse self-reported health. As the Tsimane' integrate into the market economy, their possibilities of wealth accumulation rise, which may affect their well-being. Our work contributes to recent efforts in biocultural anthropology to link the study of social inequalities, human biology, and human-environment interactions.     

The Link between Inequality and Population Health in Low and Middle Income Countries: Policy Myth or Social Reality?

An influential policy idea states that reducing inequality is beneficial for improving health in the low and middle income countries (LMICs). Our study provides an empirical test of this idea: we utilized data collected by the Demographic and Health Surveys between 2000 and 2011 in as much as 52 LMICs, and we examined the relationship between household wealth inequality and two health outcomes: anemia status (of the children and their mothers) and the women'' experience of child mortality. Based on multi-level analyses, we found that higher levels of household wealth inequality related to worse health, but this effect was strongly reduced when we took into account the level of individuals'' wealth. However, even after accounting for the differences between individuals in terms of household wealth and other characteristics, in those LMICs with higher household wealth inequality more women experienced child mortality and more children were tested with anemia. This effect was partially mediated by the country''s level and coverage of the health services and infrastructure. Furthermore, we found higher inequality to be related to a larger health gap between the poor and the rich in only one of the three examined samples. We conclude that an effective way to improve the health in the LMICs is to increase the wealth among the poor, which in turn also would lead to lower overall inequality and potential investments in public health infrastructure and services.     

Individual health and the visibility of village economic inequality: Longitudinal evidence from native Amazonians in Bolivia

Mounting evidence suggests that income inequality is associated with worse individual health. But does the visibility of inequality matter? Using data from a horticultural-foraging society of native Amazonians in Bolivia (Tsimane’), we examined whether village inequality in resources and behaviors with greater cultural visibility is more likely to bear a negative association with health than village inequality in less conspicuous resources. We draw on a nine-year annual panel (2002–2010) from 13 Tsimane’ villages for our main analysis, and an additional survey to gauge the cultural visibility of resources. We measured inequality using the Gini coefficient. We tested the robustness of our results using a shorter two-year annual panel (2008–2009) in another 40 Tsimane’ villages and an additional measure of inequality (coefficient of variation, CV). Behaviors with low cultural visibility (e.g., household farm area planted with staples) were less likely to be associated with individual health, compared to more conspicuous behaviors (e.g., expenditures in durable goods, consumption of domesticated animals). We find some evidence that property rights and access to resources matter, with inequality of privately-owned resources showing a larger effect on health. More inequality was associated with improved perceived health – maybe due to improved health prospects from increasing wealth – and worse anthropometric indicators. For example, a unit increase in the Gini coefficient of expenditures in durable goods was associated with 0.24 fewer episodes of stress and a six percentage-point lower probability of reporting illness. A one-point increase in the CV of village inequality in meat consumption was associated with a 4 and 3 percentage-point lower probability of reporting illness and being in bed due to illness, and a 0.05 SD decrease in age-sex standardized arm-muscle area. In small-scale, rural societies at the periphery of market economies, nominal economic inequality in resources bore an association with individual health, but did not necessarily harm perceived health. Economic inequalities in small-scale societies apparently matter, but a thick cultural tapestry of reciprocity norms and kinship ties makes their effects less predictable than in industrial societies.     

Do Markets Worsen Economic Inequalities? Kuznets in the Bush

Integration into a market economy or economic development can erode the quality of life of indigenous people by, for example, increasing income inequalities. The Kuznets hypothesis predicts that the link between income inequality and income (a proxy for economic development) resembles an inverted U. We test the hypothesis using a survey of 511 households from 59 villages of Tsimane' Amerindians, a horticultural-foraging society in the tropical rain forest of Bolivia. We measure village inequalities of three economic outcomes: income, imputed annual value of rice production, and wealth. We used three indices of inequality: the coefficient of variation, the standard deviation of the logarithm, and the Gini coefficient. Explanatory variables include either income and income squared, wealth and wealth squared, or imputed annual rice production and production squared. We used village-to-town distance as a control. We find little evidence that integration to the market increases inequalities of economic outcomes, with two exceptions: Wealth bore the predicted inverted U-shaped relation with wealth inequalities, and imputed rice production bore a U-shaped relation to inequality, but only when (a) using adult equivalents to express household size and (b) the Gini coefficient and the coefficient of variation to measure inequality; in no case were results robust to different econometric specifications. We advance several explanations for why economic development might not accentuate economic inequalities among relatively autarkic rural economies.     

Child health inequality in Sub-Saharan Africa

We investigate child height inequality and inequality of predicted height in the Sub-Saharan Africa (SSA) region by socioeconomic, demographic and geographical factors. We characterize their changes in age-cohorts (from 0‐1 up to 4‐5 years old) and determine the contribution of each factor to these changes. We extract data from the Demographic and Health Surveys (DHS) for 33 SSA countries covering the period from 2009 to 2016. Our measure of health is the standardized height of children below the age of five, adjusted by the age and gender distribution in each country. We show that height inequality is lower for older children than for their younger peers. However, the share of inequality caused by our set of factors rises along the age distribution in more than 80% of countries. We find that family background (reflected by maternal education and the household wealth), followed by home infrastructures related to water, toilet and cooking facilities, and the region of residence contribute to explaining the differences observed in child health inequality along the age distribution in SSA.     

Increased Morbidity and Mortality in Domestic Animals Eating Dropped and Bitten Fruit in Bangladeshi Villages: Implications for Zoonotic Disease Transmission

We used data on feeding practices and domestic animal health gathered from 207 Bangladeshi villages to identify any association between grazing dropped fruit found on the ground or owners directly feeding bat- or bird-bitten fruit and animal health. We compared mortality and morbidity in domestic animals using a mixed effects model controlling for village clustering, herd size, and proxy measures of household wealth. Thirty percent of household heads reported that their animals grazed on dropped fruit and 20% reported that they actively fed bitten fruit to their domestic herds. Household heads allowing their cattle to graze on dropped fruit were more likely to report an illness within their herd (adjusted prevalence ratio 1.17, 95% CI 1.02–1.31). Household heads directly feeding goats bitten fruit were more likely to report illness (adjusted prevalence ratio 1.35, 95% CI 1.16–1.57) and deaths (adjusted prevalence ratio 1.64, 95% CI 1.13–2.4). Reporting of illnesses and deaths among goats rose as the frequency of feeding bitten fruit increased. One possible explanation for this finding is the transmission of bat pathogens to domestic animals via bitten fruit consumption.     

Obesity inequality and well-being in Germany

Using 2002–2018 German Socio-Economic Panel (GSOEP) data for German adults aged 18 + , this study measures changes in the body mass index (BMI) distribution and obesity inequality to estimate the relation between the latter and subjective well-being. In addition to documenting a significant association between the various measures of obesity inequality and subjective well-being, especially among women, we show a significant increase in obesity inequality, particularly among females and those with low education and/or low income. This rising inequality points to the need to combat obesity through initiatives targeted at specific sociodemographic groups.     

Do human parents face a quantity‐quality tradeoff?: Evidence from a Shuar community

A number of evolutionary theories of human life history assume a quantity-quality tradeoff for offspring production: parents with fewer offspring can have higher biological fitness than those with more. Direct evidence for such a tradeoff, however, is mixed. We tested this assumption in a community of Ecuadorian Shuar hunter-horticulturalists, using child anthropometry as a proxy for fitness. We measured the impact of household consumer/producer (CP) ratio on height, weight, skinfold thicknesses, and arm and calf circumferences of 85 children and young adults. To control for possible "phenotypic" correlates that might mask the effect of CP ratio on anthropometry, we also measured household garden productivity, wealth, and social status. Regression models of the age-standardized variables indicated a significant negative impact of CP ratio on child growth and nutrition. The age-standardized height and weight of children in households with the largest CP ratio (10) were 1.38 and 1.44 standard deviations, respectively, below those of children in households with the smallest CP ratio (2). Surprisingly, garden productivity, wealth, and status had little to no effect on the fitness proxies. There was, however, an interesting and unexpected interaction between status and sex: for females, but not males, higher father status correlated significantly with higher values on the proxies.     

Fertility decline and the changing dynamics of wealth,status and inequality

In the course of demographic transitions (DTs), two large-scale trends become apparent: (i) the broadly positive association between wealth, status and fertility tends to reverse, and (ii) wealth inequalities increase and then temporarily decrease. We argue that these two broad patterns are linked, through a diversification of reproductive strategies that subsequently converge as populations consume more, become less self-sufficient and increasingly depend on education as a route to socio-economic status. We examine these links using data from 22 mid-transition communities in rural Poland. We identify changing relationships between fertility and multiple measures of wealth, status and inequality. Wealth and status generally have opposing effects on fertility, but these associations vary by community. Where farming remains a viable livelihood, reproductive strategies typical of both pre- and post-DT populations coexist. Fertility is lower and less variable in communities with lower wealth inequality, and macro-level patterns in inequality are generally reproduced at the community level. Our results provide a detailed insight into the changing dynamics of wealth, status and inequality that accompany DTs at the community level where peoples'' social and economic interactions typically take place. We find no evidence to suggest that women with the most educational capital gain wealth advantages from reducing fertility, nor that higher educational capital delays the onset of childbearing in this population. Rather, these patterns reflect changing reproductive preferences during a period of profound economic and social change, with implications for our understanding of reproductive and socio-economic inequalities in transitioning populations.     

Body mass,wealth, and inequality in the 19th century: Joining the debate surrounding equality and health

We explore relationships among BMI variation, wealth, and inequality in the 19th century US. There was an inverse relationship between BMI and average state-level wealth and a small, inverse relationship with wealth inequality. After controlling for wealth and inequality, farmers had greater BMI values than workers in other occupations, and blacks had greater BMI values because of nutritional deprivation in utero.     

Rich-poor gap in utilization of reproductive and child health services in India, 1992-2005

This paper examines the trends in utilization of five indicators of reproductive and child health services, namely, childhood immunization, medical assistance at delivery, antenatal care, contraceptive use and unmet need for contraception, by wealth index of the household in India and two disparate states, Uttar Pradesh and Maharashtra. The data from three rounds of the National Family and Health Survey conducted during 1992-2005 are analysed. The wealth index is computed using principal component derived weights from a set of consumer durables, land size, housing quality and water and sanitation facilities of the household, and classified into quintiles for all three rounds. Bivariate analyses, rich-poor ratio and concentration index are used to understand the trends in utilization of, and inequality in, reproductive and child health services. The results indicate huge disparities in utilization of these services, largely to the disadvantage of the poor. Utilization of basic childhood immunization among the poorest and the poor stagnated in India, as well as in both states, during 1998-2005 compared with 1992-1998. The use of maternal care services such as medical assistance at delivery and antenatal care remained at a low level among the poor over this period. However, contraceptive use increased relatively faster among the poor, even with higher unmet need. Of all these services, the inequality in medical assistance at delivery is consistently large, while that of contraceptive use is small. The state-level differences in service coverage by wealth quintiles over time are large.     

DNA methylation mediates the impact of exposure to prenatal maternal stress on BMI and central adiposity in children at age 13? years: Project Ice Storm

Prenatal maternal stress (PNMS) in animals and humans predicts obesity and metabolic dysfunction in the offspring. Epigenetic modification of gene function is considered one possible mechanism by which PNMS results in poor outcomes in offspring. Our goal was to determine the role of maternal objective exposure and subjective distress on child BMI and central adiposity at 13½ years of age, and to test the hypothesis that DNA methylation mediates the effect of PNMS on growth. Mothers were pregnant during the January 1998 Quebec ice storm. We assessed their objective exposure and subjective distress in June 1998. At age 13½ their children were weighed and measured (n = 66); a subsample provided blood samples for epigenetic studies (n = 31). Objective and subjective PNMS correlated with central adiposity (waist-to-height ratio); only objective PNMS predicted body mass index (BMI). Bootstrapping analyses showed that the methylation level of genes from established Type-1 and -2 diabetes mellitus pathways showed significant mediation of the effect of objective PNMS on both central adiposity and BMI. However, the negative mediating effects indicate that, although greater objective PNMS predicts greater BMI and adiposity, this effect is dampened by the effects of objective PNMS on DNA methylation, suggesting a protective role of the selected genes from Type-1 and -2 diabetes mellitus pathways. We provide data supporting that DNA methylation is a potential mechanism involved in the long-term adaptation and programming of the genome in response to early adverse environmental factors.     

Nutritional Consequences of Wealth Differentials in East African Pastoralists: The Case of the Datoga of Northern Tanzania

Among African pastoralists evidence that wealth is associated with other measures of household success is scant and the significance of wealth differentials for family welfare remains poorly understood. Predictions that wealth in livestock is associated with increased adequacy of household food supply and with improved child nutrition are tested with longitudinal data on herd size, household composition, food supply, and anthropometric status collected in 1992 for a sample of traditional Datoga households (n = 20) living in the Eyasi basin in northern Tanzania. Although a majority subsisted below poverty cutoffs estimated for east African pastoral populations, there was large variation among households in measures of wealth and resource availability. Individuals in relatively wealthy households did not appear to benefit either in terms of adequacy of household food supply or in terms of average growth performance of young children. Theoretical and methodological challenges in the study of the relationship between wealth and health in nomadic pastoralists are discussed.     

Inequality in Disability in Bangladesh

Objective

To investigate inequality in disability in Bangladesh.

Methods

The study used both household level and individual level data from a large nationally representative data set, Bangladesh’s Household Income and Expenditure Survey - 2010. Principal component analysis was used to construct a wealth index based on household assets from household level data. Then, using data from 49,809 individuals aged 5 years and over, chi-square tests and logistic regression were performed to test the association between wealth level and disability.

Findings

Women and older people are significantly more likely to report having disabilities than men and younger people. For middle and rich families, respectively, there is a 14 percent lower likelihood of reporting disabilities than for poor families. Changes in the probability of having disabilities are linear with increasing wealth. In addition, the study identifies some significant factors affecting disability, namely, age, sex, education, marital status, and place of residence including divisional differences.

Conclusion

In Bangladesh, worse health among the poor argues for policies prioritizing this group while at the same time giving special attention to women and the elderly.     

Association of Household and Community Socioeconomic Position and Urbanicity with Underweight and Overweight among Women in Pakistan

Background

Similar to other developing countries, Pakistan is going through a rapid nutrition transition where shift from underweight to overweight and obesity is occurring. In this paper, we report on the relationship of household socioeconomic position (SEP), community SEP and urbanicity with under- and over-weight categories of BMI among Pakistani women.

Methods

We analyzed data on 4,767 women ages 15-49 years enrolled in a nationally representative Pakistan Demographic Health Survey (PDHS) conducted in 2012-13 that employed a multistage, stratified cluster sampling design. We assessed the association of urbanicity, household and community SEP derived from household assets and utilities, with categories of body mass index (BMI) using multinomial regression analysis where normal weight (BMI 18.6-22.5) was the reference category.

Results

Thirteen percent of women were underweight (BMI <18.5), 15% pre-overweight (BMI: 22.6-24.9), 25% overweight (BMI: 25.0–29.9) and 14% were obese (BMI≥30). Pre-overweight, overweight and obesity among women increased across household wealth quintiles (HWQs) in a graded fashion whereas there was no significant difference in underweight by household wealth. Women in urban areas were more likely to be obese. There was a pronounced increase in adjusted odds ratios (aORs) for overweight/obesity across HWQs within urban areas compared to rural areas. There was a steeper gradient in aORs for obesity from 1st to 5th HWQs in high income communities compared to the middle- and low income communities. In community-level analyses, communities in urban areas were more likely to have higher levels of obesity while in rural areas, especially in Sindh, more communities were more likely to have a higher level of underweight.

Conclusion

A shift to higher overweight and obesity than underweight in Pakistan is associated with high household and community wealth as well as living in urban areas. Clustering of obesity and underweight in distinct communities afford opportunity for tailored intervention programs.     

Poverty or income inequality as predictor of mortality: longitudinal cohort study.

OBJECTIVE: To determine the effect of inequality in income between communities independent of household income on individual all cause mortality in the United States. DESIGN: Longitudinal cohort study. SUBJECTS: A nationally representative sample of 14,407 people aged 25-74 years in the United States from the first national health and nutrition examination survey. SETTING: Subjects were followed from initial interview in 1971-5 until 1987. Complete follow up information was available for 92.2% of the sample. MAIN OUTCOME MEASURES: Relation between both household income and income inequality in community of residence and individual all cause mortality at follow up was examined with Cox proportional hazards survival analysis. RESULTS: Community income inequality showed a significant association with subsequent community mortality, and with individual mortality after adjustment for age, sex, and mean income in the community of residence. After adjustment for individual household income, however, the association with mortality was lost. CONCLUSIONS: In this nationally representative American sample, family income, but not community income inequality, independently predicts mortality. Previously reported ecological associations between income inequality and mortality may reflect confounding between individual family income and mortality.     

Association of socioeconomic status with successful ageing: differences in the components of successful ageing

This study sought to determine which factors among the indicators of socioeconomic status have the most influence on physical, mental and social functions, and on subjective well-being, all of which are components of successful ageing. A representative random sample of 1825 persons aged 65 years or older was surveyed by face-to-face interview. Socioeconomic status was measured by educational level, family household income, personal income and property ownership. The factors measured were chronic diseases, activities of daily living (ADL) for physical functioning, history of mental disease, Mini-Mental Status Examination questionnaire (MMSE) scores for mental functioning, social activity participation per week for social functioning, and the Philadelphia Geriatric Center Morale Scale (PGCMS) for subjective well-being. Multiple logistic regression analyses were performed. Education level was the most important factor in physical and mental functioning, whereas personal income was the most important in social functioning. Educational level, household income and personal income were significantly associated with subjective well-being as assessed by PGCMS scores. Subjects who demonstrated successful ageing were more likely to have a higher education and higher personal income. The results point to the importance of focusing on disparities in each component of successful ageing, which may point to appropriate health-promotion strategies for eliminating inequality in successful ageing.     

The hidden penalties of gender inequality: fetal origins of ill-health

This paper is concerned with the interconnections between gender inequality and maternal deprivation, on the one hand, and the health of children (of either sex) and of adults that the children grow into (again, of either sex). The basic message of the paper is that women's deprivation in terms of nutrition and healthcare rebounds on the society as a whole in the form of ill-health of their offspring-males and females alike-both as children and as adults. There are a variety of pathways through which women's deprivation can affect the health of the society as a whole. This paper focuses on the pathways that operate through undernourishment of the mother. Maternal deprivation adversely affects the health of the fetus, which in turn leads to long-term health risks that extend not just into childhood but into adulthood as well. There are, however, important differences in the way children and adults experience the consequences of maternal deprivation via fetal deprivation. In particular, the pathways that lead to their respective risk factors and the circumstances under which those risk factors actually translate into ill-health are very different. These differences are best understood through the concept of 'overlapping health transition' in which two different regimes of diseases coexist side by side. Gender inequality exacerbates the old regime of diseases among the less affluent through the pathway of childhood undernutrition. At the same time it also exacerbates the new regime of diseases among the relatively more affluent through a pathway that has come to be known as the 'Barker hypothesis'. Gender inequality thus leads to a double jeopardy-simultaneously aggravating both regimes of diseases and thus raising the economic cost of overlapping health transition.     

Wealth transmission and inequality among hunter-gatherers

We report quantitative estimates of intergenerational transmission and population-wide inequality for wealth measures in a set of hunter-gatherer populations. Wealth is defined broadly as factors that contribute to individual or household well-being, ranging from embodied forms such as weight and hunting success to material forms such household goods, as well as relational wealth in exchange partners. Intergenerational wealth transmission is low to moderate in these populations, but is still expected to have measurable influence on an individual's life chances. Wealth inequality (measured with Gini coefficients) is moderate for most wealth types, matching what qualitative ethnographic research has generally indicated (if not the stereotype of hunter-gatherers as extreme egalitarians). We discuss some plausible mechanisms for these patterns, and suggest ways in which future research could resolve questions about the role of wealth in hunter-gatherer social and economic life.     

Identifying the limits to socioeconomic influences on human growth

Contemporary humans occupy the widest range of socioeconomic environments in their evolutionary history, and this has revealed unprecedented environmentally-induced plasticity in physical growth. This plasticity also has limits, and identifying those limits can help researchers: (1) parse when population differences arise from environmental inputs or not and (2) determine when it is possible to infer socioeconomic disparities from disparities in body form. To illustrate potential limits to environmental plasticity, we analyze body mass index (BMI) and height data from 1,768,962 women and 207,341 men (20–49 y) living in households exhibiting 1000-fold variation in household wealth (51 countries, 1985–2017, 164 surveys) across four world regions—sub-Saharan Africa, South Asia, Latin America, and North Africa and the Middle East. We find that relationships of environmental inputs with both mean height and BMI bottom out at roughly 100–700 USD per capita household wealth (2011 international units, PPP), but at different basal BMIs and basal heights for different regions. The relationship with resources tops out for BMI at around 20 K–35 K USD for women, with growth potential due to environmental inputs in the range of 6.2–8.4 kg/m². By contrast, mean BMI for men and mean height for both sexes remains sensitive to environmental inputs even at levels far above the low- and middle-income samples studied here. This suggest that further work integrating comparable data from low- and high-income samples should provide a better picture of the full range of environmental inputs on human height and BMI. We conclude by discussing how neglecting such population-specific limits to human growth can lead to erroneous inferences about population differences.