Becker Friedman Institute
for Research in Economics
The University of Chicago

Research. Insights. Impact. Advancing the Legacy of Chicago Economics.

Student Spotlight: Carrie Wenjing Xu

Carrie Wenjing Xu is going into her fifth year as a PhD student at the University of Michigan. As the University’s first joint Economics and Information Science doctoral student, she combines elements from several disciplines in order to understand human behavior. Her interests include labor and behavioral economics, with topics related to social networks, peer effects, and belief formation.  She is one of few experimentalists attending this year’s Summer School on Socioeconomic Inequality.

Xu holds a master’s degree in economics from Michigan, as well as a bachelor’s degree in economics with an applied mathematics minor from Shanghai Jiaotong University in China. She also spent time at Universität Mannheim in Germany as a Business and Economics exchange student.

I applied to the Summer School to gain exposure to different perspectives on how equality matters and to learn advanced research methods that I can apply to my future work on the ways information and social elements can affect inequality.

Carrie, how did you become interested in economics, and why did you decide to attend the Summer School on Socioeconomic Inequality?

I have always been fascinated by how people make decisions and the thought processes that lead to the behaviors we observe. The two key determinants that I am keen to understand are information and social influence. How does information change one’s expectations and decisions? How do people influence each other’s behavior? In my mind, these two can be instrumental for policy design. For example, employers need to design appropriate mechanisms to disseminate performance feedback, which can affect an employee’s self-perceptions and future productivity.  Understanding how social influence transmits in a workplace can help managers engineer positive synergies amongst workers.

I applied to the Summer School to gain exposure to different perspectives on how equality matters and to learn advanced research methods that I can apply to my future work on the ways information and social elements can affect inequality. I was very much looking forward to the lectures on networks and social structures given by Professor Blume and Professor Durlauf.

Can you describe your current research on social influence and peer effects?

My work on social influence is motivated by the fact that many decisions we make are impacted by our friends, families, coworkers – basically, the people around us. The effect of these influences can play a role in where we choose to work, how hard we work, what products we try, etc. I designed a field experiment that investigates the effects of social networks on college students in a large introductory statistics course. I’m interested in how friends affect each other’s effort and performance. To answer that question, I first elicited detailed network data to identify and track study partnerships. I then randomly gave some students advice about studying for an exam. I watched how my intervention diffused across the study buddy network. Like watching drops of ink diffusing in a glass of water, I’m interested in how the effect of advice radiates through the network.

And I do find that the ink spreads. My effort measures come from the user data generated by an online learning applet tailored to this course, and we do observe positive peer effects, or spillovers, amongst partners. For example, if your partner had the advice intervention, but you did not, I observe an increase in your study efforts as compared to students who did not have access to the intervention, either directly or through their partners. I also find that strong tie partners cast a stronger influence than weak tie partners.  

This research is one of the few studies in education that shows causal peer effects. The results have implications for promoting peer interactions to spread positive influences. Policy-wise, my hope is to pair up social networks and targeted intervention in order to scale up positive impacts and minimize the gap between well-connected and isolated individuals.

The other key factor you mentioned is information. Do you have any research projects along that line?

Although only in the very early stages I have another project that contrasts two performance feedback mechanisms. One information structure compares an individual to a “local” group and the other to a “global” group. These two structures are frequently seen in the real world. SAT/ACT scores are global performance measures, as one is compared to almost all other test takers. GPA, on the other hand, provides local performance measures because one is compared to schoolmates with similar background performance. I ask whether local versus global measures impact individual beliefs and willingness to compete differently.

To answer that question, I designed a lab experiment because belief updating is hard to observe and measure outside the lab. In my experiment, subjects need to decide whether to compete with other subjects in a math task. After a practice round, subjects with above median performance are more likely to be sorted into group A, and the rest are assigned to group B. Subjects are told about their group assignment under both information structures. The key difference is that under the local information structure, subjects receive information comparing them to their group members, those with similar performance. Under the global information structure, subjects are compared to everyone else, including group B members.

While I designed the two structures so that, in theory, there should be no differences in beliefs or actions, several cognitive biases may reject the theoretical predictions. Under the local information scenario, subjects in the high performance group (group A) may mistakenly think that they are low performers when their performance is worse than others in their group. This misperception can happen if subjects care more about individual comparison and neglect their group standing.

My design can also be used to study gender differences in belief updating. Psychology research has shown that men tend to attribute success to themselves and failures as external, whereas women are more likely to reverse those attributions and have a more difficult time taking compliments. The implications of these attribution biases and the way we process different types of performance feedback connects to heated discussions and a growing body of literature on why females tend to shy away from competition.

Can you describe your recent experience at the Summer School on Socioeconomic Inequality in Chicago?

I was very impressed by the faculty speakers, who introduced us to a broad range of interesting topics. The presentations covered a lot of areas, delivering complex information in a nice, digestible way. The speakers also provided us with extensive reading lists, so we can dig deeper into specific topics of interest.

The faculty office hour was also a very nice feature of the event – it allowed us a one-on-one opportunity to ask questions and seek help and feedback with our own research. I got a lot of inspiration from these world-renowned researchers, and I could tell they were sincere in their desire to help.

I learned a lot from the poster session, too. I gained valuable experience in presenting a pitch; I had to grab the audience’s attention quickly and synthesize and deliver the gist in 10 minutes. I gained experience in handling questions on the fly as well.

I was also very impressed by the diversity of the students – there were representatives of many disciplines, including economics, sociology, and education. There were a lot of synergies amongst the students.

Were there any sessions that especially stood out to you or which were particularly useful and applicable to your research?

I really enjoyed hearing Jeff Smith from Michigan. He has a very smooth and clear way of talking through technical information, theories, examples, and applications. Flávio Cunha from Rice University was also excellent. During his talk on human capital accumulation, he shared state of the art methods. He is a gifted presenter. And, of course, Steve Durlauf’s lecture on social inequality really highlighted his knowledge across disciplines. When he talks, he not only refers to economics research, but he also speaks fluently about sociology, psychology, and anthropology, mixing all of them into an inspiring presentation.

Is there anything else you’d like to add about your experience at the Summer School this year?

There were several economics summer camps happening at the University at the same time – the Price Theory Summer Camp, the Summer Institute on Field Experiments, and the SSSI. It was great to meet students from these other events. We were able to catch up and talk about what we were learning during each of our programs. It was a great mix and a nice surprise to connect with some old friends and make new friends.

Held over the summer across three international sessions, the 2016 Human Capital and Economic Opportunity Global Working Group Summer Schools on Socioeconomic Inequality provide a state-of-the-art overview on the study of inequality and human flourishing. The summer schools are one of a host of summer research activities highlighted in this series. To learn more, please visit our summer research hub.

—Tina Cormier