Janet Currie investigates the building blocks of children’s success

Janet Currie

Janet Currie PHOTO BY DENISE APPLEWHITE

By Michael Hotchkiss

TRAINED AS A LABOR ECONOMIST, Janet Currie earned her doctorate at Princeton by studying strikes and arbitration. But as she began her academic career in the late 1980s, she shifted her focus to examining the building blocks of success for children, as well as the stumbling blocks that can get in their way.

While the topics are very different, Currie said both benefit from research by economists. “I realized that economics is really more of a method, or a way of thinking, than a set of topics, and I have implemented that by working on issues that can benefit from the tools of economics research,” she said.

Over the nearly three decades since, Currie has used the methods of an economist, her analytical skills and an openness to new ideas to offer important insights into the health and well-being of children. In the terms of economics, she studies the factors that affect children’s human capital — the intangible assets such as health, skills and knowledge that play a role in life outcomes.

Today the Henry Putnam Professor of Economics and Public Affairs at Princeton and chair of the Department of Economics, Currie has tackled research on a wide range of topics, including socioeconomic differences in child health, environmental threats to children’s health and the long-term effects of poor health in early childhood.

Beyond the individual findings, Currie said, are broader lessons.

“One would be that very early life is important,” she said. “That is now pretty well accepted and has had an impact on policy, but at the time I was starting to do this research that wasn’t so widely appreciated. Another kind of general conclusion is that pollution at lower levels than Environmental Protection Agency thresholds for concern has measureable and detectable health effects.”

Currie joined the Princeton faculty in 2011 from Columbia University. Previously, she was on the faculty at the University of California-Los Angeles and the Massachusetts Institute of Technology.

At Princeton, Currie is director of the Center for Health and Wellbeing, which fosters research and teaching on aspects of health and well-being in developed and developing countries. She is also a senior editor of the Future of Children, a publica- tion that translates social science research about children and youth into information that is useful to policymakers, practitioners and other nonacademic audiences.

Sara McLanahan, a Princeton sociologist who works with Currie on projects including the Future of Children and shares many of her research interests, said Currie is “one of the most outstanding economists in the country who is doing work on child health.” And, McLanahan added, Currie’s impact goes beyond her research.

“She’s just very willing to give her time and be generous,” said McLanahan, the William S. Tod Professor of Sociology and Public Affairs. “She’s a straight shooter. She tells you what she thinks. She does more than her share, and she wants it to be done right. She’s just a great positive force.”

An economist’s approach

Currie, who earned her bachelor’s and master’s degrees in economics from the University of Toronto before coming to Princeton for her doctoral studies, said several aspects of economics make it useful in studying children and their outcomes.

Among them: a tradition of using models to frame issues, an emphasis on measurement and a focus on establishing causal relationships.

Often, she has applied these principles in natural experiments, which are observational studies where conditions outside a researcher’s control randomly assign some people to an experimental condition and others to a control condition.

For example, interest in the impact of pollution on infant health led Currie and Reed Walker, then a graduate student at Columbia and now an assistant professor at the Haas School of Business at the University of California-Berkeley, to examine the effect of introducing electronic toll collection on the health of children born to mothers who lived near toll plazas. They found that the switch to electronic toll collection, which greatly reduced traffic congestion and vehicle emissions near toll plazas, was associated with a decline in premature and low-birth-weight babies born to those mothers.

That research depended on identifying the roll-out of electronic toll collection as a potential natural experiment, gathering pollution data for the area of toll plazas, and mining birth records for the necessary information about the residences of mothers and birth outcomes.

In another natural experiment, Currie and Maya Rossin-Slater of Columbia used birth records from Texas and meteorological information to identify children born in the state between 1996 and 2008 whose mothers were in the path of a major tropical storm or hurricane during pregnancy. They found that expectant mothers who dealt with the strain of a hurricane or major tropical storm passing nearby during their pregnancy had children who were at elevated risk for abnormal health conditions at birth.

Keeping an open mind

Hannes Schwandt, who has worked closely with Currie during three years as a postdoctoral research associate at the Center for Health and Wellbeing, said another important aspect of Currie and her work is her openness to new ideas.

“On the one hand, she has this great detailed expertise, given all the work she has done,” Schwandt said. “At the same time, she’s always open to new questions. I think combining her expertise with this view for broad, new directions is what makes her so special.”

Take a paper he and Currie published in 2014 on the effect of recessions on fertility. The idea began, Schwandt said, with a discussion they had about evidence that babies born during recessions are generally healthier than those born in better times.

“Janet said we need to step back and look at fertility — who is giving birth — instead of focusing on the health of babies,” Schwandt said. “She immediately made the connection that in the news there is always a discussion that there is decline in fertility during recessions. But no one really knew the long-term effect.”

After examining 140 million births over 40 years, Currie and Schwandt found that recessions are linked to an increase in the number of women who remain childless at age 40.

What’s ahead

Currie is continuing to pursue ways to address issues relating to children and their development.

One project is looking for new evidence of the impact of lead exposure on children and their educational outcomes in Rhode Island. By matching birth records, lead-test results and school records, Currie is examining the impact of a program to reduce children’s exposure to lead.

“One of the really interesting things about this research, I think, is that the program to reduce lead exposure seems to have been pretty effective,” Currie said.

Because African American children were more likely to live in areas with high lead levels, the program brought their lead levels down more quickly than those of white children. At the same time, Currie said, the gap in standardized test scores between the groups narrowed.

The research could offer new clues about the role lead exposure plays in the lower test scores typically recorded by students who live in inner-city areas where lead exposure is more common, Currie said.

Another work in progress takes advantage of the implementation of congestion pricing in Stockholm, which levies a tax on most vehicles entering and exiting the city’s center, to measure the impact of traffic — and the resulting pollution — on child health. A third is examining state-by-state differences in smoking patterns among pregnant women and the relationship between smoking among pregnant women and low-birth-weight births.

A topic she would like to address in future work: mental health.

“I’m interested in that for a lot of different reasons,” she said. “If you look at the U.S. economy, mental health is the leading cause of lost work. That’s because it tends to strike people who are of working age, whereas a lot of other health conditions are more for older people. It’s important from an economic point of view. It also seems to be very related to a lot of learning issues.”

Over the past 20 years, Currie said, a raft of new psychiatric medications has come on the market, many of which are not well understood, and prices are rising.

“It seems like there’s this huge black box of things that are happening and no one is really studying, and there’s not very good data on it,” she said. “That’s something I’ve been struggling with for a while, how to get some purchase on that problem.”

Valued as a mentor

Currie is also widely recognized for her work with young researchers and her advocacy for them.

“In addition to all the work she does as a top economist, being willing to work with students is a great benefit,” McLanahan said. “Having someone do so well and be so generous is important, especially for the next generation of female economists.”

In spring 2015, Currie received a Graduate Mentoring Award from the McGraw Center for Teaching and Learning. Graduate students described Currie as insightful and readily available to help aspiring researchers develop their ideas and present them publicly.

Molly Schnell, a Ph.D. candidate in economics, said Currie is so generous with her time “that she seems to defy the principle of scarcity.”

In particular, she pointed to Currie’s willingness to co-author papers with graduate students.

“Learning to develop a paper by working through the process with an established researcher is a formative experience, and Janet makes sure that her students have this opportunity,” Schnell said.

Schwandt said Currie has helped him grow more confident in tackling new topics.

“One thing I’ve learned from her is not to worry too much whether other people think something is economics or not,” he said. “She always says: ‘First, who defines what economics is? And second, why do we really care so long as it is a really important question and we can help answer it?’”

Professor Janet Currie’s research uses the tools of economics research to study issues in children’s health. Among her findings:

E-Z Pass Research

 

Expectant mothers

 

 

Foreclosure research

 

 

 

Fertility research

 

 

 

 

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Fragile families, fragile children

Sara McLanahan

Sara McLanahan is the principal investigator on the Fragile Families and Child Wellbeing Study, which found that children of unmarried parents encounter a great deal of instability. (Photo by Larry Levanti)

Relationships are complicated in the best of times, but even more so for unmarried parents and their children. Children born to unmarried parents encounter considerable instability in their family life when their biological parents end relationships and form relationships with new partners, according to data from the Fragile Families and Child Wellbeing Study, an initiative spearheaded by family demography expert in the Woodrow Wilson School Sara McLanahan.

The study found that just over a third of unmarried parents who are romantically involved at birth are still together by the time their child is 5 years old, compared to 80 percent of married parents. More than 60 percent of unmarried mothers have by then also changed residential partners — that is, had one or more new partners move in or out of the household.

Children encounter an even wider cast of characters if researchers take account of mothers’ more casual dating partnerships, with more than 75 percent of unmarried mothers experiencing a change in either a co-residential or short-term dating relationship. Half-siblings are also part of the picture: nearly 50 percent of children born to unmarried mothers live with a half-sibling by the time they reach age 5.

“The bottom line is that very few children born to unmarried parents are living in stable single-mother families,” said McLanahan, the William S. Tod Professor of Sociology and Public Affairs. The Fragile Families study is funded by the Eunice Kennedy Shriver National Institute of Child Health & Human Development, the National Science Foundation, the U.S. Department of Health and Human Services, and several foundations.

That unmarried parents are more likely to have low education and income levels means that their children often fare worse as well, reporting more physical and mental health problems. Children of unmarried parents also tend to score lower on reading and math tests. McLanahan explained that while economic adversity accounts for much of this disadvantage, a high level of instability and family complexity may contribute to these negative outcomes.

–By Tara Thean

The social network: Program combats bullying

New laws and policies to address harassment and intimidation in schools are sprouting up in every state. But can laws and polices put a stop to bullying, or do students play a role?

Psychologist Elizabeth Levy Paluck has set out to demonstrate that students can change the climate of a school from one that tolerates bullying to one that promotes positive behavior. She is leading a research program in 58 New Jersey middle schools that harnesses the power of students’ social networks to change behavior and reduce bullying.

Elizabeth Paluck

Elizabeth Levy Paluck, an assistant professor of psychology and public affairs, is pursuing research in New Jersey middle schools to test whether it is possible to change social norms regarding bullying by targeting students’ social networks. (Photo by Denise Applewhite)

The project tests the premise that the best way to change social norms is to target the most socially connected people, and then allow the change to diffuse through the group, said Paluck, an assistant professor of psychology and public affairs. “People construct their ideas of acceptable behavior by observing others, especially influential individuals,” she said. “We would like to know if we can change the culture of a school by first changing the attitudes and behavior of these individuals.”

Paluck stressed that while some of these students are “popular,” others are the unofficial leaders of non-mainstream social groups organized around a common interest such as skateboarding or glee club.

Paluck is conducting the project, which is supported by the William T. Grant Foundation, the Spencer Foundation, the Canadian Institute for Advanced Research and Princeton’s Educational Research Section, with Hana Shepherd, a postdoctoral research associate in the psychology department and Princeton’s Woodrow Wilson School of Public and International Affairs.

The first step in the project, which began in fall 2012, was to identify a school’s influential students, or “social referents.” The researchers asked the entire student body to fill out a questionnaire listing the other individuals in his or her network. Privacy was preserved via use of anonymous codes. Using a mathematical algorithm, the Paluck team then constructed models of every social network in the school and combed for individuals with lots of connections within networks.

Social network

Elizabeth Levy Paluck, assistant professor of psychology and public affairs, and her team mapped the social networks of middle school students to identify influential individuals (social referents), who were then randomly assigned to either participate or not participate in an intervention program designed to reduce conflict in schools. In a pilot study, the researchers found that students (first-degree and second-degree connections) in the networks of social referents who participated in the antibullying program were less likely to view conflict as acceptable at the school, and were less likely to be disciplined for peer conflict, compared to students in networks of social referents who did not participate in the intervention program. (Original illustration courtesy of Elizabeth Levy Paluck.)

Once identified, some of these well connected individuals were randomly selected to join a group where they learned about bullying prevention and created an intervention program to spread positive social norms through efforts such as student assemblies, posters and wristbands. “It was important that the students design the program, to ensure that it meets their needs,” Paluck said.

Prior to starting the intervention program, the researchers conducted a baseline survey of attitudes toward bullying. At the end of the 2012-13 school year, the team conducted a follow-up survey of attitudes and collected information on behaviors. While the New Jersey results are not yet in, a pilot project in a school in Connecticut found improvements in attitudes about bullying and in reduced incidents of harassment and intimidation.

The much larger New Jersey study should allow the researchers to compare schools that received the intervention to those that did not. Within each school, the researchers can compare the attitudes and behaviors of students who belong to the networks of socially influential students who participated in creating antibullying interventions to students in the networks of influential students who did not participate.

“We need to know whether we changed the climate of conflict, did we set into motion a new expectation of what behaviors are desirable, did we make an overall difference?” Paluck said. “You cannot test this with only one social network, you have to compare to other networks where intervention was not done.”

–By Catherine Zandonella

Site-specific shades offer sun protection

Sun shade

Civil and environmental engineering graduate student Matthew Horner sits with Assistant Professor Sigrid Adriaenssens beneath a prototype of a pavilion designed to block harmful UV radiation by accounting for the sun’s path within its specific geographic location. (Photo by Denise Applewhite)

Children exposed to a lot of sunlight have a higher chance of developing skin cancer as adults, according to the Centers for Disease Control and Prevention. With this in mind, structural designer and assistant professor in the Department of Civil and Environmental Engineering Sigrid Adriaenssens is creating a sun shade designed to account for the sun’s path within a specific geographic location. This would allow the shade to work anywhere, protecting against the sun’s power and helping reduce skin cancer — the most common form of cancer in the United States.

Adriaenssens’ approach is to produce a dome shaped grid for the sun shade that works with surrounding climatic conditions and uses the least amount of building material possible. To do this, her team uses data from the National Oceanic and Atmospheric Administration and NASA coupled with their sun path algorithms to identify specific sunlight angles in the sun shade’s location and ensure that the grid shades for only those angles. This allows the structure to block damaging UV radiation, but lets through light that doesn’t affect the target shade area.

The inspiration for the shade’s design came in part from existing commercial sun shades, which are typically “one design fits all” and thus ineffective at actually shading their target areas. Individuals sitting under a patio set with a sun shade, for example, can find that the perimeter of the table around which they are sitting is not shaded at all, Adriaenssens explained.

Adriaenssens uses a “dialectic” strategy in her work, which is a reference to the dialectic form of discourse that looks for a solution to a problem by using various arguments, or design drivers in this case. For Adriaenssens, the drivers include engineering considerations such as structure and material as well as questions of environmental performance.

“I think sometimes you can design, in a very economic way, very elegant systems,” she said, noting that she encourages the dialectic approach among her students. Adriaenssens’ colleagues, including Assistant Professor of Civil and Environmental Engineering Mark Zondlo, Postdoctoral Research Associate Landolf Rhode- Barbarigos, and graduate students Matthew Horner and Dan Reynolds, recently erected a prototype sun shade near the Princeton University Stadium.

Other sun-related projects that adapt to different environmental conditions are on Adriaenssens’ radar. One of her models takes its cue from plants such as the waterwheel plant (Aldrovanda vesiculosa), which uses two lobes that rapidly snap shut to catch prey. The mechanics of this motion serve as the basis for shading structures that open and close based on the amount of sunlight present at a given time, ensuring lower manufacturing costs and energy consumption.

Adriaenssens hopes that the high efficiency of her creations will ensure a low-resource path to useful designs, especially in cities. With 70 percent of the world population predicted to live in urban environments by 2050, carbon emissions from existing and additional buildings — and the construction materials for creating them — required to support their needs will only increase, she explained.

“We must find more efficient ways to provide people with a good quality of life using fewer resources,” she said. “My research is all about how we can develop an engineering design framework for a future-oriented urban environment.”

–By Tara Thean