Emma Zang, a demographer and visiting research scholar at Princeton’s Center for Health and Wellbeing (CHW), has long been intrigued by the relationships between health, family and inequality. In this Spotlight, Zang explains how her upbringing, cultural influences – and even a few imaginary siblings – affected the course of her education and career.
Assistant professor of sociology and biostatistics at Yale University, Zang shares her background and work examining the impact of early-life conditions on future decisions and health outcomes. She highlights her interests in demographic and socioeconomic inequalities, as well as climate change, and explains how her research could play a role in developing policy to shape population health in the United States, China and other countries around the world.
Q. Given your interest in life course perspectives, I’m curious if and how your own early-life experiences may have influenced your research and career.
A. I was born in the northern part of China and was part of a birth cohort that has been through a lot of changes, both in society and in the economy. Much of my research has been inspired by personal experiences and the experiences of people I know. For example, like many of my cohorts in China, I am the only child in my family, which has a lot of implications for the way I think about things and the research topics I select. I was a lonely kid growing up, so I created imaginary siblings and often wondered how my life would be different if I had actual siblings. This led to my work on sibling effects and spillovers.
One paper, for instance, examines how having an academically successful older sibling may impact younger siblings’ educational outcomes – and how these effects may differ by socioeconomic background. The general story I find is that having an academically successful older sibling has a positive effect on younger siblings’ educational attainment and that the spillover effect is particularly large among disadvantaged families.
Also, as an undergraduate, I thought a lot about social mobility and mental health. I wondered if people who are more successful are happier or less happy than those who are not successful. I wanted to answer this question for society and for myself. My first published paper explored the issue and found that upward mobility does not have a positive effect on mental health, particularly among people of color. To achieve success, those faced with structural barriers work harder, sacrifice more, have more stress, and have health consequences attached to their social mobility.
Q. Tell me about your undergraduate and master’s studies in mainland China and Hong Kong.
A. My first college major was actually law, which you can study as an undergraduate in China. After a year of courses, I became extremely interested in divorce law. But I was more interested in the aspect of gender inequality than the legal aspect. I wanted to understand something deeper. I wanted to know what is behind the tragedies of divorce, why so many women have difficulty getting a divorce, and why they do not receive equal property. I could not answer those questions perfectly from a legal perspective, which led me to take more courses in sociology and to think about how gender norms, institutions and societal expectations have shifted the legal system in China. In fact, part of my dissertation examined the impact of a significant change in the country’s divorce law.
Q. After studying the social sciences, you pivoted by earning an M.A. in economics and a Ph.D. in public policy at Duke University. What drew you to these disciplines?
A. In China, the field of sociology is very qualitative, more like anthropology. At Hong Kong University of Science and Technology, however, I had the opportunity to work with two demographers from the United States, which increased my interest in quantitative research. One of these professors saw the future of social science as interdisciplinary and created this kind of environment, so I had courses in quantitative analysis, psychology, political science and other disciplines. I liked it so much that I wanted to continue my training, particularly in economics and demography, so I would have more tools to study gender inequality, health disparities and other topics.
I applied to a lot of different graduate programs in the United States and eventually chose to pursue a Ph.D. in public policy because I wanted my research to be useful. Particularly in the Chinese context, public policies are driven more by the philosophies of political leaders than scientific research. I believe that evidence-based research could make policies more effective.
Q. You mentioned that your dissertation studied divorce law change in China. Can you share more about this research?
A. Because China’s population is skewed and has a lot more men than women (due to gender preferences), not every man can find a wife. This creates a supply-demand situation where grooms are expected to provide a “bride price” before marriage. In modern society, the “bride price” is a family home. Before 2011, upon divorce, the home was considered joint property and was typically awarded to the woman as a type of compensation, allowing the mother and children to stay in the home. But in 2011 the Chinese Supreme Court changed the law to state that the home is the property of the person whose name is on the deed – usually the husband.
My research critically examined the consequences of this legal change, which was disastrous for women. The law sent a message that women who dare to divorce will lose a huge amount of property. Unsurprisingly, I found that that the new law had a negative impact on the happiness of women, who felt less secure and less confident about the future.
Q. After earning your Ph.D., you joined the faculty at Yale University. Why did you choose a career in higher education?
A. If you want to be a serious researcher, academic jobs are among the best choices because universities give you a lot of flexibility in terms of research topics. When I was on the job market, I already had several journal articles and a bunch of book chapters published. I wanted to continue this focus on research, so I explored opportunities in sociology, public policy, and public health and was fortunate to find a position in the Sociology Department at Yale.
I also enjoy mentoring students and find teaching a very rewarding practice. I like to shape their future directions, encouraging them as they apply for Ph.D programs and consider careers. Working with these talented students is helpful to my research as well, contributing different perspectives and topic ideas. In fact, I have co-authored articles with many students, even undergraduates.
Q. You consider yourself a demographer whose research interests lie at the intersection of health, family and equality. How are these areas intertwined, and why does the space intrigue you?
A. I did a lot of demographic research when I was in Hong Kong, so much of my early work focused on mortality outcomes, which is very closely related to health. I looked at how people die, and when they die, but I also wanted to understand what happened to their health when they were alive. That led to my interest in examining health disparities in general.
The family aspect is more related to my interest in gender inequality. For example, I find that in the United States, China, and many countries, the educational attainment of women has surpassed the educational attainment of men. But if you look at the wage difference, you see that men still earn so much more money than women. It doesn’t make any sense. What happens? Through my research, I’ve observed that intrafamily equality is often overlooked. The women in households tend to do most of the housework and child care, which drags down their professional productivity, shifts career outcomes, and therefore affects their income.
Q. I noticed that some of your most recent research explores the impact of climate change on population health. What inspired this interest?
A. At Yale, I’ve worked a lot with the School of Public Health and the School of Medicine on environmental issues and their impact on health outcomes, which has become a major public health concern in recent decades. I’ve seen a significant amount of progress in this field, inspiring projects with some of my colleagues who have overlapping research interests, such as environmental epidemiologists. For example, I co-authored a paper looking at how long-term exposure to ozone affects people’s cognitive functioning later in life. I also hired some Princeton students to assist with a project on how air pollution exposure affects children’s test scores. Climate change definitely will be an ongoing topic in my research.
Q. What brought you to Princeton’s Center for Health and Wellbeing as a visiting research scholar?
A. My research is highly interdisciplinary, including collaborations with clinicians, economists, mathematicians and other sociologists. After working at Yale for two years, I saw this opportunity and thought it was the perfect position and environment for me. It fits my methodological training, and also a lot of demographers at Princeton are affiliated with this center.
Q. What has been the focus of your research during your time here?
A. I’ve worked on a lot of different projects during my visit. Among the highlights are new partnerships to further explore the topic of sibling spillovers. My initial study was done in the context of North Carolina, where I did my Ph.D. work and had access to public school records. For example, I started a project with Professor Dalton Conley in the Department of Sociology, also affiliated with the Center for Health and Wellbeing, where we are trying to incorporate genetic data to capture the biological endowment of each sibling within the family and to also observe the parents’ investment behaviors. We’re trying to find out if parents disproportionately invest in the child whom they observe as smarter, or if they overcompensate with the less talented child to balance sibling outcomes.
As another extension of my North Carolina project, I’m working with an economics professor, Chris Nielson, who has access to amazing data from Chili, and I’m leading a global project on sibling spillover effects. We have located collaborators with access to public school records in more than 10 countries to further examine the consequences of having an academically successful older sibling by looking at younger siblings’ test scores. We’re also investigating whether or not these effects differ between various family backgrounds.
Q. In 2021, you were awarded a sizable grant from the National Institute on Aging for a project examining the health trajectories of individuals with cognitive impairment and their caregivers in the United States. Have you advanced this project during your visit to Princeton?
A. This is my first big grant, nearly half a million dollars, which is a considerable amount for this stage in my career. I have had the opportunity to work on this project at Princeton. In fact, I’ve already written a couple of articles about some interesting findings. For example, I found that most people with cognitive impairment in the U.S. experienced dramatic declines in their physical health during the eight-year study period. However, some of these individuals also experienced improvement in their depression symptoms over time. In other words, their mental health got better despite the fact that their physical health status became worse.
Another interesting aspect of this research concerns racial disparities. My work consistently finds that Black and Hispanic Americans have lower baselines in terms of chronic disease and other health markers compared to white Americans with cognitive impairment. Also, the speed of health declines in Hispanic, Asian and Native Americans is faster compared to all of the other racial and ethnic groups. These particular groups are among the most understudied populations because of data limitations and are therefore a priority in my research.
Q. Anything else in the pipeline, in terms of your research?
A. All of my current research interests fit into the broad categories of family and health, including my studies on siblings, divorce law, environmental issues, and health disparities. In the next five years, I want to finish all of the projects I started. I will spend a lot of time on the sibling projects, especially the two that I mentioned; they are big and involve international collaborations. I’m very excited for that. I also will complete my grant work on cognitive impairment and health trajectories and have started a project examining the implications of the transition to remote work – before, during and after the Covid pandemic – on the younger generation that is entering the labor market.
Q. Earlier, you underscored the importance of your research being useful. Could you elaborate on how your work could have a meaningful impact on global health and wellbeing?
A. I think this research could be used in multiple ways, especially with regard to policy. First of all, we already know that bad things happen more often in disadvantaged families. My research shows that the younger siblings in these families suffer the most; they are not only affected directly but also have natural spillover effects from their older siblings’ experiences. If we could give a subsidy or some kind of support to disadvantaged families, then the younger siblings could have positive spillovers. Such policies would offer a social safety net and provide enormous benefit to these children.
Another example concerns the cut-off date for school entry. My doctoral research studied the cut-off date in North Carolina. In that state, children born by October 16 can enter kindergarten while children born after that date must wait another year. I found that students born before October 16 have significantly better academic performance compared to children born after that date because the former are older and typically have better leadership skills and higher maturity. Also, we know that White boys from advantaged families are more likely to delay school entry on purpose, a practice called “redshirting,” which leads to a bigger Black-White achievement gap. My research suggests that implementing a later school entry date would reduce “redshirting” behaviors, narrow the age difference in classes, and shrink the racial achievement gap.
I hope that my research can contribute to policy-making and help vulnerable populations, including people of color, women and immigrants. Even a little bit would be enough.
Q. Can we end with a fun fact? What is something your colleagues or students may not know about you?
A. I have a super cute dog, a standard poodle, which is somewhat of a celebrity on campus and in my community. His picture is often featured in my slides – and in my teacher evaluations. My students love him!