Affluent People Research Articles

The geography of the global super-rich

Over the past decade or so, there has been increasing concern over rising inequality and the growth of the 1 percent of super-rich people who sit atop the global economy. While studies have charted the super-rich by industry and nation, there is very little research on their location by city or metro area. Our research uses detailed data from Forbes (2015) on the world’s billionaires to test a series of hypotheses about the location of the super-rich across the world’s cities and metro areas. We find that the super-rich are concentrated in a small number of metros around the world and that their location is primarily related to the size of metros: Large metros offer more people bigger markets, more diversified industries and more opportunity that help produce and attract billionaires. The location of the super-rich is more modestly associated with living standards (measured as economic output per capita) and less so with the presence of finance and tech industries, and city competitiveness. Their location is not related to quality of life, which is somewhat surprising in light of the level of mobility the super-rich enjoy, as well as research that finds that affluent and talented people are attracted to higher quality, higher amenity places.

Testing Differential Associations Between Smoking and Chronic Disease Across Socioeconomic Groups: Pooled Data From 15 Prospective Studies.

For the same quantity of cigarettes smoked, relative to more affluent people, socioeconomically disadvantaged people have higher levels of smoking biomarkers. This may be ascribed to inhaling cigarette smoke more deeply and more frequently and/or choosing higher tar-containing brands. We investigated whether this increased tobacco load, as captured using cotinine measurements, is associated with a greater risk of mortality in lower social groups. We used Cox proportional hazards models stratified by socioeconomic position to calculate hazard ratios in a pooled sample of 15 English and Scottish prospective cohort studies (N = 81,476). During a mean (SD) follow-up of 10.3 (4.4) years, 8234 deaths occurred. Risk of total mortality (hazard ratio; 95% confidence interval) for smokers relative to never-smokers in the high (2.5; 2.1, 3.1), intermediate (2.1; 1.8, 2.4), and low (2.0; 1.9, 2.2) educational groups did not differ markedly (P for interaction=0.61). Similar findings emerged when using cause-specific outcomes and occupational social class and housing tenure as socioeconomic indices. Contrary to our hypothesis, we found no indication that chronic disease mortality associated with smoking was higher in disadvantaged people.

The condition and destruction of the socialization function of local rural communities

Despite progressing urbanization, Poland essentially is a country village. Poland’s ruralness – if it is understood as that part of the country that is outside of cities, occupies more than 90% of the country’s territory. In Poland, within rural areas, we have over 43 thousand so-called basic settlement units. Since 1950, the number of the largest villages (over 1000 inhabitants) and large villages (over 500–1000 inhabitants) located close to the cities has been systematically growing and the dynamics of their number and population growth shapes the phenomenon of gentrification (settling in the countryside of the urban population mainly representing the middle class) in tandem with their depreciation and largely proletarianization. Residents of rural areas make up about 40% of the Polish population, revealing an upward trend, dealing with their existence in various, not necessarily traditional and effective ways. Thus, the percentage of affluent people and those experiencing social or material mires increases in Polish villages. This material stratification of the population of Polish villages, families inhabiting them, raises new disturbing phenomena and states of affairs, and their growth dynamics are shaped, among others, the above – mentioned by the processes of gentrification, deagrarianization and proletarianization of village communities.

Communities of Color Are More Vulnerable to Wildfires

Affluent white people are more likely to live in fire-prone areas, but race and socioeconomic vulnerability can put minority communities at greater risk, a new study finds.

Language, food and gentrification: signs of socioeconomic mobility in two Gothenburg neighbourhoods

This paper examines at how language and food intersect and interact in gentrificationprocesses. As a capital-driven social process aiming at enhancing the socioeconomicvalue of urban space, gentrification implies mobility both in the sense that it attractsnew people, businesses and capital to an area, and in the form of displacement ofless affluent and prestigious people, businesses and semiotic resources from centralto marginal urban spaces. The paper examines linguistic and visual traces of suchmobilities in two neighbourhoods in Gothenburg, Sweden. Based on the observationthat food and food practices are central for the production and reproduction of socialdistinction, the analysis centres on food related establishments and signs. In particular,it discusses the distinction-making function of prestigious languages, elite gastronomicregisters, and gourmet food trucks, and how these depend on the marginalizationof low status languages, popular gastronomic registers and cheap generic food carts.People’s interaction with these resources contributes to the reconfiguration of socialand urban space.

Grappling with flying as a driver to climate change: Strategies for critical scholars seeking to contribute to a socio‐ecological revolution

Airplane flights are one of the fastest, perhaps even the fastest, growing source of greenhouse gas emissions, even though there is much discussion of mitigating emissions to stave off a global climate change disaster. While business people, politicians, celebrities, and highly affluent people appear to be the most frequent flyers, the demands of an increasingly corporatised university sector have placed much pressure on academics, including anthropologists, to fly to attend conferences and meetings and conduct research. I seek to grapple with the dilemmas involved in the academic use of aircraft, particularly on the part of those academics who accept the gravity of anthropogenic climate change spurred on by the demands of global capitalism, and propose some strategies for mitigating climate change on the part of anthropologists in particular as part of the larger project of creating a socio‐ecological revolution that will contribute to a safe climate.

Breaking niche sustainable products into the mainstream: Organic milk and free‐range eggs

AbstractWe contribute to the existing literature on factors influencing sustainable product consumption behavior by (a) employing actual supermarket sales data from over 300 outlets in England covering up to 18 million customers, and by (b) examining two products that can both be labeled as sustainable but have very different market positions: organic milk as a typical niche product, and free‐range eggs which (based on market share) can be seen as a mainstream product. Our study has looked into the influence of factors such as deprivation and race, which have not previously been looked into. The results partially confirm previous research, which is mostly based on self‐reported behavior, identifying both price and deprived catchment areas as barriers but green attitudes as a facilitator while more affluent people purchase organic milk. What is new from our work is that convenience stores have a negative influence and for organic milk, older families and those aged 25–44 years have a positive influence. Crucially, we identify clear differences between purchasing behaviors regarding niche and mainstream products in our analysis: while purchases of organic milk can be predicted by a wide range of sociodemographic factors, this is not the case for free‐range eggs. Here, besides price and green attitudes, there are no other influences on behavior. The results of our study can therefore provide fresh insight into the debate around recent attempts to mainstream sustainable product consumption.

A Study on the Work-Life Balance Issues Faced by Micro and Small Village Entrepreneurs (MSVEs) in India

This paper aims at appreciating the need for and relevance of understanding conceptual paradigm of Work-Life Balance, and Rural Entrepreneurs who are conceptualized as Micro and Small Village Entrepreneurs (MSVEs). Enterprises in rural environments are operating in an arena of extreme and rapid change. In India, entrepreneurship has traditionally been considered a prerogative of affluent urban people. However, in tandem with a changing socio-cultural environment and an increase in educational opportunities, people from rural context have started recognizing their inherent talents and business skills. With the help of various governmental and non-governmental agencies, growing numbers of people from small villages and towns in the country are joining the ranks of entrepreneurs. However, in the existing familial and societal setup, such Micro and Small Village Entrepreneurs (MSVEs) are overburdened and find it increasingly difficult to balance their work and life roles. Therefore, the major objective of the present study was to understand and illustrate the work-life balance (WLB) issues faced by such Micro and Small Village Entrepreneurs (MSVEs) of the states of Haryana and Rajasthan in India. In this context, data has been collected by area sampling (cluster-random) paired with semi-structured interviews and a questionnaire. This study revealed that role overload, dependent care issues, quality of health, problems in time management and lack of proper social support are the major factors influencing the WLB of MSVEs entrepreneurs in India. Furthermore, even though the vast majority of the entrepreneurs examined in this study suffer from WLB issues, there are significant differences in the level of WLB issues faced by the various categories of MSVEs entrepreneurs.

Collective efficacy in disadvantaged neighborhoods: The influence of Habitat for Humanity

ABSTRACTIn this study, we examine neighborhood poverty and the problems with which it is associated. Much of housing policy is based on the assumption that poor people need more affluent people around them to solve these problems. We argue instead that individual motivation to better one’s life may have a larger impact on surrounding neighbors, especially if these individuals are similar in race and income. We investigate low-income neighborhoods characterized by a large presence of Habitat for Humanity homeowners in five U.S. cities to determine whether their Habitat residents’ motivation to better their lives has a spillover effect on their neighbors. Through a comparative multiple case study design, we examine the collective efficacy of these census blocks and find that there is a positive “Habitat effect” on these neighborhoods. However, we find that the local Habitat affiliate characteristics, number and development pattern of Habitat houses present, and level of neighborhood disadvantage are also key contextual variables in determining any positive effect on their neighborhoods. Our conclusions provide lessons for local Habitat affiliates, as well as policymakers, planning agencies, and housing advocates.

A ‘Great Change’, or, the Poles’ Unfulfilled Daydream about Having a Car (1956–7)

The political ‘Thaw’ of 1956–7 was in Poland a period of thorough political as well as cultural and social change. While the political liberalisation came to an end rather soon, the team of Wladyslaw Gomulka, the newly-appointed First Secretary of the Central Committee of the Polish United Workers’ Party [PZPR], in power since October 1956, cared much for maintaining and reinforcing their pro-social and reformatory image. The leadership team’s assent for a more sophisticated consumption, part of which was owning a car, helped alleviate social tensions. The models were drawn from the West of Europe and from the United States, which for the Polish society were the major points of reference, as well as from the other socialist countries – particularly, East Germany (the GDR) and Czechoslovakia, where the political and societal significance of motorisation had already been appreciated. On the other hand, offering private individuals an opportunity to purchase a car was meant to be a remarkable tool used to draw the ‘hot money’ down from the market, thus preventing inflation. Cars, imported or Polish-made, began being (relatively) freely traded, at very high prices. This did not limit the demand, as acquiescence for private business operations contributed to the growing of the group of affluent people. While this incited the citizens to develop their own strategies of acquiring cars – not infrequently colliding with the law; the authorities began gradually reinstating the rationing. All the same, the number of private cars quickly increased, to 58,600 as of 1958, up from some 24,750 in 1956. Public discussion started around popular low-capacity (small-engine) cars – whether licensed (Renault, Simca, Fiat) or (to be) made in Poland. However, in spite of the raised expectations the authorities decided that it was still too early for a mass motorisation: this was made possible only in the early 1970s.

Obstruction of justice in the effort to eradicate corruption in Indonesia

Corruption is a reality in Indonesia and has a significant destructive force. Not only does it harm the wealth of the state, but it also takes away the legitimacy of law enforcement by destroying the public's trust in law. This can lead to the destruction of democracy and modernization in Indonesia. Aware of the situation, or perhaps for political correctness, the post independence governments made the war on corruption a state of emergency. But it was not until the advent of the political era known to the Indonesians as Era Reformasi in 2000 that the fight against corruption intensified with the enactment of Law No. 30/2002 creating the Corruption Eradication Commission or Komisi Pemberantasan Korupsi (hereafter referred to as KPK). Since its creation, the Commission has been hunting down corruptors like never before. But going after corrupt officials is not an easy task. As KPK gets tougher due to more legal backup and public's trust, corruptors find illegal ways to bend, or impede the law in order to get away with their heinous crime. This practice is known as obstruction of justice. This paper discusses the issue of obstruction of justice in the effort to eradicate corruption in Indonesia. It sets out to answer the following questions: what does obstruction of justice in the corruption eradication effort look like in Indonesia, and how can law enforcement agencies best deal with it. Drawing on empirical data, the study reveals that an act is deemed obstructing justice if it is done intentionally to prevent the legal process from running smoothly (mens rea). Although anyone is susceptible of committing an act of obstruction of justice, it is usually accomplished with the support of affluent people such as government and law enforcement officials, lawyers, and law makers. The study suggests that revising laws on corruption, continuing collaboration between law enforcement agencies, making use of the existing corruption-related laws, increasing law enforcement professionalism, and raising public awareness need to be embraced as future approaches to heighten the ongoing war on corruption.

NHS dental service utilisation and social deprivation in older adults in North West England.

Objective To explore NHS dental service utilisation (attendance and treatment activity) of older adults.Design Retrospective analysis of dental treatment claim forms (FP17s) over a 15 month period.Population A total of 690,433 older adults in North West England.Results NHS dental care attendance decreased with increasing age; 49% in 65-74 years, 39% in 75-84 years and 23% in the over 85 years age group. Across all older age stratifications, the more deprived patients had a higher rate of examinations, extractions, dentures and preventative advice compared to the least deprived patients. However, the relationship was opposite for the rate of fillings and complex restorative treatment; the rate was higher for the least deprived older adult patients.Conclusions Despite 95% of older adults living in the community, the number of older adults accessing NHS dental care in this data set is thought-provoking. Additionally, there is a complex relationship between the type of treatment provided and the patient's IMD level. The authors acknowledge the major limitations of this dataset; affluent people are more likely to access private dental care and the availability of NHS dental services is likely to vary across different regions. However, the use of 'big data' is necessary to provide a pragmatic approach for future research in the management of older adults in general dental services.

Chronic Kidney Diseases in Children, Management Difficulties and Amelioration in Bangladesh: A Review

Background: Bangladesh is a small country of south Asia with a population of 153 million, among them 66 million are under age of 18years. The exact prevalence of chronic kidney disease (CKD) in children is not well known due to lack of a national registry. But in Bangabandhu sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh, the incidence is 7.9% in 2013 and there are approximately thirty five hundred thousand around the country. There are 4.4% of children with renal disease prevalent in the country. But unfortunately, there is diagnostic problem and the treatment facility is very limited. Only few centers provide the renal replacement therapy in this country and only two centers do pediatric renal transplantation. So, to tackle this large burden with very limited resource, it is important to try and reduce the incidence of chronic kidney disease, especially end stage renal disease. We can handle the present situation with our existing resource with some modification of health care delivery system with contribution from government, non government organizations (NGO'S) and affluent people. This article highlights chronic kidney disease in children, present treatment modality and some fiiture directive to handle such a crucial problem, thus may help thousands of children from such a devastating situation.J Shaheed Suhrawardy Med Coll, 2015; 7(1):26-32

REDEFINITION OF LUXURY FASHION BRANDING THROUGH SUSTAINABILITY RENAISSANCE: RE(F)USE CASE

The luxury fashion industry is a global multi-billion dollar industry including a wide array of brands with massive halo effect, brand heritage and high consumer relevance such as Fendi, Prada, Louis Vuitton, Gucci and Hermes which are also among the most valuable and influential brands in the world. The established traditional methods of luxury marketing mostly focused on product innovation and exclusive brand advertising practices. With a perspective to built up a synergy between its historical heritage and the requirements of (post)modern business, the global luxury branding industry is at present facing an important challenge in consumer behavior and also going through several managerial shifts such as use of business concepts like brand equity, to e-business; and the evolution of the concepts of sustainability, recycling, provenance and fair trade applications on luxury brands. Expansion of the luxury consumer market toward a broader mass market; competition from accessible fashion brands; the redefinition of the luxury concept of the consumer society; the emergent luxury markets like China, Russia and India; and the increase and fluctuations in the world’s affluent markets and finally changing attitudes and consumption patterns in luxury pose a challenge for luxury fashion brand management. This study exemplifies this shift through an accessible luxury brand discovered on a business trip made to Rome in April 2016 by the author to study established Italian luxury brands. The new Renaissance in luxury branding idea dawned on the author through a brand named RE(f)USE founded by one of the daughters of Anna Fendi, Ilaria Venturini Fendi, the Italian luxury brand artisan. RE(f)USE is a luxury brand concept in accessories based upon the three R’s: Reduce, reuse and recycle. The three R’s have been making their way into the fashion world with new force in recent years. The story of this new off-Roman iconoclastic Italian brand as a strong and valid example that uses recycled and upcycled materials to keep waste to a minimum while creating beautifully unique luxury products the consumers find extremely inspiring and relevant will be depicted in the study. The evolution and redefinition of luxury idea from high-fashion looks to eco-conscious downshifting with upcycled stuff, made from recycled materials will be pinpointed. As a result in response to affluenza, we also see a new luxury consumer, the post-luxury consumer, willing to participate in the voluntary simplicity movement as socially conscious affluent people expressing a variety of concerns about environment, overconsumption, abuse of developing nations and extensive advertising and this deserves further analysis.

From a Disaster to a Miracle: Suggestions for North Korea

(ProQuest: ... denotes formulae omitted.)I. IntroductionThis study attempts to discover what North Korea can do to revive its economy with particular attention to three salient facts. First, the per capita income of North Korea grew from approximately $750 to around $1,514 from 1953 to 2014.1 North Korea is as poor as it was before.2 Second, its population grew from approximately 10 million in 1953 to nearly 25 million at present. North Korea has succeeded in feeding a growing population. Third, income disparity exists between a small class of affluent people and the majority of poor people.3The average income of North Korea has remained virtually stagnant in the face of the doubling up of the population over the last 60 years. This fact suggests that it may have been a Malthusian subsistence economy, in which income stagnation and population growth can coexist.A single class Malthusian model cannot explain the existing elite class of North Koreans who live more affluently than others do. By contrast, a dual-class Malthusian model can easily explain the phenomenon. In an economy in which a small number of property owners (i.e. masters) force a large number of property-less workers (i.e. slaves) to work for the former, masters can live affluently.Solutions for a dual-class economy, which we analyze in the first part of this study, indicate that workers barely subsist, whereas owners live prosperously. Numerical exercises performed with the proposed model show that the long-term stationary state income of a worker is $630 and that of an owner is $6,300. A master can be ten times wealthier than a slave is.What would happen if slaves become free? How would things change when everyone becomes an egalitarian owner? Our model shows that the long-term stationary per capita income would go up to $2,100. That is, if the slavery were abolished, the average income of the former slaves would increase from $630 to $2,100. By contrast, the income of the former masters decreases sharply from $6,300 to $2,100; a master must sacrifice two-thirds of his former income.A master would not willingly forego such privilege. Nevertheless, inducing masters to free their slaves is possible (e.g. with bribery). Transferring a portion of the increased income of former slaves to their former masters can be such a scheme. Former slaves can have larger income even after transfers.However, this kind of transfer cum slave liberation scheme may not work in reality. Slaves who are freed may not uphold their promises. They may even try to punish former masters. With this knowledge, masters will not free the slaves unless they become convinced that the freed slaves will abide by their commitment. A mechanism is needed to ensure that slaves are freed and that the freed slaves will not only forgive the former masters but also give them sufficient compensation. Nobody seems to know what this mechanism is, which possibly explains why North Koreans are stuck with dictatorial masters.We organize the paper as follows. In Section II, we propose and solve a slavery model. The goal is to derive closed-form solutions with which we may enhance our understanding of North Korea. Then, in Section III, we undertake numerical exercises with solutions derived in Section II. The exercises provide us with vivid pictures of how the proposed model would behave in real situations. In Section IV, we attempt to understand the North Korean economy in light of the analyses made in Sections II and III. We also suggest what North Korea can do to revive its economy and engineer unceasing economic growth. Finally, in Section V, we conclude the study. II. Slave Economy: An Adaptation of Lucas' ModelsThis section studies slave economy models, which are adaptations of Lucas' 2002 paper. We consider two models: i) land only model and ii) land plus physical capital model. Once we derive solutions to the slave economy models, we compare them with the solutions of Lucas' one class models. …

Medical Tourism Development in Dubai: Managing Challenges and Opportunities

Objective – International medical travel is one of the fastest growing and lucrative segments of the tourism industry of this century. In the past, affluent people from Middle Eastern countries travelled abroad to the UK or USA for medical surgery and not wealthy citizens from developed countries are seeking affordable, accessible, world class quality of healthcare with modern medical technology, no waiting lists and combining it with a holiday. Dubai has established itself as a destination that can offer all this to foreign medical travellers. Methodology/Technique This paper is exploratory in nature and provides a conceptual study to investigate the expansion, challenges and economic opportunities for developing, promoting and managing Dubai as a medical tourism destination, which is a unique contribution to the theory of medical tourism management. Findings The study indicated several interesting findings regarding challenges such as highly dependence of UAE on foreign human resources, providing safety to migrant workers, implementing integrated medical tourism policy, global health insurance transferability, establishing legal and regulatory issues and others. Novelty : This paper has presented ground breaking findings indicating the issues faced by the Dubai Government regarding the growth and sustainability of medical tourism.The lack of direct access to the Dubai Government and medical tourists is a limitation of this study. Type of Paper: Review Keywords: Dubai; Medical Travel; Tourism; Development; Healthcare Management.

Daily chocolate consumption is inversely associated with insulin resistance and liver enzymes in the Observation of Cardiovascular Risk Factors in Luxembourg study.

This study examined the association of chocolate consumption with insulin resistance and serum liver enzymes in a national sample of adults in Luxembourg. A random sample of 1153 individuals, aged 18-69 years, was recruited to participate in the cross-sectional Observation of Cardiovascular Risk Factors in Luxembourg study. Chocolate consumption (g/d) was obtained from a semi-quantitative FFQ. Blood glucose and insulin levels were used for the homoeostasis model assessment of insulin resistance (HOMA-IR). Hepatic biomarkers such as serum γ-glutamyl-transpeptidase (γ-GT), serum aspartate transaminase and serum alanine transaminase (ALT) (mg/l) were assessed using standard laboratory assays. Chocolate consumers (81·8 %) were more likely to be younger, physically active, affluent people with higher education levels and fewer chronic co-morbidities. After excluding subjects taking antidiabetic medications, higher chocolate consumption was associated with lower HOMA-IR (β=-0·16, P=0·004), serum insulin levels (β=-0·16, P=0·003) and γ-GT (β=-0·12, P=0·009) and ALT (β=-0·09, P=0·004), after adjustment for age, sex, education, lifestyle and dietary confounding factors, including intakes of fruits and vegetables, alcohol, polyphenol-rich coffee and tea. This study reports an independent inverse relationship between daily chocolate consumption and levels of insulin, HOMA-IR and liver enzymes in adults, suggesting that chocolate consumption may improve liver enzymes and protect against insulin resistance, a well-established risk factor for cardiometabolic disorders. Further observational prospective research and well-designed randomised-controlled studies are needed to confirm this cross-sectional relationship and to comprehend the role and mechanisms that different types of chocolate may play in insulin resistance and cardiometabolic disorders.

Abstract P142: Daily Chocolate Consumption is Inversely Associated with Insulin Resistance and Liver Enzymes in Adults: The Observation of Cardiovascular Risk Factors Study

Introduction: Research into the health effects of cocoa has received much attention over the past few years. Several systematic reviews and meta-analyses of existing studies have generally agreed on a potentially beneficial association between chocolate consumption and risk for cardiometabolic disorders. However, evidence regarding a potential role of chocolate consumption in insulin resistance and hepatic biomarkers, from human epidemiological studies, is lacking. Hypothesis: We assessed the hypothesis that daily chocolate consumption would be inversely associated with insulin resistance and hepatic biomarkers in appraently healthy adults. Methods: A random sample of 1153 individuals, aged 18-69 years, was recruited between 2007 and 2009 to participate in the Observation of Cardiovascular Risk Factors (ORISCAV-LUX) study. Chocolate consumption in g/day was obtained from a semi-quantitative food-frequency questionnaire. Blood glucose and insulin were used for the homeostasis model assessment of insulin resistance (HOMA-IR). Hepatic biomarkers, namely serum γ-glutamyl-transpeptidase (γ-GT), serum Aspartate Transaminase (AST) and serum Alanine Transaminase (ALT) in mg/l were assessed using standard laboratory assays. Results: Chocolate consumers (81.8 %) were more likely to be younger, physically active, affluent people with higher education levels and have fewer chronic comorbidities. After exclusion of subjects taking antidiabetic medications, higher chocolate consumption was associated with lower HOMA-IR (β= -0.16, P=0.004), serum insulin levels (β= -0.16, P=0.003), and liver enzymes, including γGT (β= -0.12, P=0.009) and ALT (β= -0.09, P=0.004) after adjustment for age, sex, education, lifestyle (smoking status and physical activity) and dietary confounding factors, including daily energy intake, consumption of fruit and vegetables, alcohol, as well as polyphenol-rich coffee, and tea. Conclusion: This is the first population-based study reporting an independent inverse relationship between daily chocolate consumption and levels of insulin, HOMA-IR and liver enzymes in adults.. Small dietary changes with respect to chocolate consumption may improve liver enzymes and protect against insulin resistance, a well-established risk factor for cardiometabolic disorders.

Urban-Suburban Migration in the United States, 1955-2000

This study uses census microdata from 1960 to 2010 to look at the rates of suburbanization in the 100 largest metro areas. Looking at the racial and ethnic composition of the population, and then further breaking down these groups by income, it’s clear that more affluent people were more likely to move to the suburbs. Also, the White non-Hispanic population has long been the most suburbanized group. A majority of the White population lived in suburbs by 1960 in the 100 largest metro areas, while most of the Black non-Hispanic population lived in urban core areas as late as 2000. The Hispanic and Asian populations went from majority urban to majority suburban during this period.

Erratum: “Bias in Environmental Cohort Studies: The Example of Bone Lead and Mortality”

Unrecognized biases in prospective environmental cohort studies may result in under- or overestimating the health effects of the exposure under investigation. In this issue of EHP, researchers examine the problem of bias using data on lead exposure and mortality in men and directed acyclic graphs (DAGs) to illustrate causal relationships between variables that could bias results.1 The study data came from 835 white male participants, average age 67 years, who were part of the Normative Aging Study (NAS), which began in 1963. Between 1991 and 1999, the men had undergone measurement of lead in their patellas. For the current analysis, the researchers looked at associations between patella lead and mortality from all causes, from cardiovascular disease, and from ischemic heart disease. Bone lead, rather than blood lead, is a better biomarker for cumulative environmental exposure,2 and patella lead in particular has been associated in past studies with risk of ischemic heart disease death.3 Directed acyclic graphs helped researchers pinpoint areas where bias related to recruitment and participation may have affected the Normative Aging Study and similar studies. The authors used DAGs to visualize relationships among variables that applied to the NAS participants. DAGs link variables with directional arrows to identify those that may bias results. The present study focused on potential errors related to participant selection and participation issues that may affect other cohort studies used in environmental health research. By explicitly visualizing assumptions with DAGs, researchers can identify where bias creeps in and find ways to avoid it.4 “Researchers don’t always recognize the assumptions they make when analyzing data,” says study leader Marc Weisskopf, an epidemiologist at the Harvard T.H. Chan School of Public Health. As the team analyzed the DAGs, they realized that age at enrollment appeared to be influencing the risk associations. Overall, men with the highest patella lead levels were twice as likely as those with the lowest lead levels to die from ischemic heart disease. However, among the subset of 637 men who were 45 or younger when they entered the NAS cohort, those with the highest patella lead levels were estimated to be 4.6 times as likely to die from ischemic heart disease as those with the lowest levels. When the data were further adjusted to account for men who dropped out of the cohort, the estimated risk among younger men with the highest lead levels climbed to 5.2 times that of younger men with the lowest exposures.1 Men who were older when they enrolled in the NAS likely did not represent older men in general. That’s because many older men have cardiovascular conditions, which makes them less likely to participate in studies.5 Furthermore, the NAS specifically did not accept participants with pre-existing cardiovascular disease.1 In contrast, because younger people tend to be healthier, their health status is less likely to influence whether they enter a study. Ideally, long-term studies such as the NAS would follow younger participants for a longer time to avoid recruitment biases. However, the longer a cohort is followed, the more expensive the study becomes. “This is particularly problematic with environmental exposures that are related to health conditions that affect people’s likelihood of participating in studies,” Weisskopf says. “Younger people are healthier to start, and it’s less likely that a health condition drives who enters a study.” Socioeconomic status presents another source of potential bias. Less affluent people are both more likely to be exposed to environmental toxicants and less likely to participate in epidemiological studies, and those who do enroll are more likely to drop out.6 “It’s not random who drops out of a cohort,” notes Weisskopf. Aside from the bias-related findings, the results suggest that previous estimates of lead’s influence on mortality may have been overly conservative. “They hint that we may be underestimating the health effects of other environmental toxicant exposures as well, especially in the context of health outcomes in older people and/or exposures associated with selection and attrition,” says Jennifer Weuve, an associate professor of internal medicine at Chicago’s Rush Medical College, who was not involved in the analysis. She says the methods used by Weisskopf’s team could be applied to other environmental epidemiology cohorts to improve estimates of health risks.