Around 2010, Facebook was a relatively small company with about 2,000 employees. So, when a PhD student named Dean Eckles showed up to serve an intership at the firm, he landed in a position with some real duties.
Eckles essentially became the primary data scientist for the product manager who was overseeing the platform’s news feeds. That manager would pepper Eckles with questions. How exactly do people influence each other online? If Facebook tweaked its content-ranking algorithms, what would happen? What occurs when you show people more photos?
As a doctoral candidate already studying social influence, Eckles was well-equipped to think about such questions, and being at Facebook gave him a lot of data to study them.
“If you show people more photos, they post more photos themselves,” Eckles says. “In turn, that affects the experience of all their friends. Plus they’re getting more likes and more comments. It affects everybody’s experience. But can you account for all of these compounding effects across the network?”
Eckles, now an associate professor in the MIT Sloan School of Management and an affiliate faculty member of the Institute for Data, Systems, and Society, has made a career out of thinking carefully about that last question. Studying social networks allows Eckles to tackle significant questions involving, for example, the economic and political effects of social networks, the spread of misinformation, vaccine uptake during the Covid-19 crisis, and other aspects of the formation and shape of social networks. For instance, one study he co-authored this summer shows that people who either move between U.S. states, change high schools, or attend college out of state, wind up with more robust social networks, which are strongly associated with greater economic success.
Eckles maintains another research channel focused on what scholars call “causal inference,” the methods and techniques that allow researchers to identify cause-and-effect connections in the world.
“Learning about cause-and-effect relationships is core to so much science,” Eckles says. “In behavioral, social, economic, or biomedical science, it’s going to be hard. When you start thinking about humans, causality gets difficult. People do things strategically, and they’re electing into situations based on their own goals, so that complicates a lot of cause-and-effect relationships.”
Eckles has now published dozens of papers in each of his different areas of work; for his research and teaching, Eckles received tenure from MIT last year.
Five degrees and a job
Eckles grew up in California, mostly near the Lake Tahoe area. He attended Stanford University as an undergraduate, arriving on campus in fall 2002 — and didn’t really leave for about a decade. Eckles has five degrees from Stanford. As an undergrad, he received a BA in philosophy and a BS in symbolic systems, an interdisciplinary major combining computer science, philosophy, psychology, and more. Eckles was set to attend Oxford University for graduate work in philosophy but changed his mind and stayed at Stanford for an MS in symbolic systems too.
“[Oxford] might have been a great experience, but I decided to focus more on the tech side of things,” he says.
After receiving his first master’s degree, Eckles did take a year off from school and worked for Nokia, although the firm’s offices were adjacent to the Stanford campus and Eckles would sometimes stop and talk to faculty during the workday. Soon he was enrolled at Stanford again, this time earning his PhD in communication, in 2012, while receiving an MA in statistics the year before. His doctoral dissertation wound up being about peer influence in networks. PhD in hand, Eckles promptly headed back to Facebook, this time for three years as a full-time researcher.
“They were really supportive of the work I was doing,” Eckles says.
Still, Eckles remained interested in moving into academia, and joined the MIT faculty in 2015 with a position in MIT Sloan’s Marketing Group. The group consists of a set of scholars with far-ranging interests, from cognitive science to advertising to social network dynamics.
“Our group reflects something deeper about the Sloan school and about MIT as well, an openness to doing things differently and not having to fit into narrowly defined tracks,” Eckles says.
For that matter, MIT has many faculty in different domains who work on causal inference, and whose work Eckles quickly cites — including economists Victor Chernozhukov and Alberto Abadie, and Joshua Angrist, whose book “Mostly Harmless Econometrics” Eckles name-checks as an influence.
“I’ve been fortunate in my career that causal inference turned out to be a hot area,” Eckles says. “But I think it’s hot for good reasons. People started to realize that, yes, causal inference is really important. There are economists, computer scientists, statisticians, and epidemiologists who are going to the same conferences and citing each other’s papers. There’s a lot happening.”
How do networks form?
These days, Eckles is interested in expanding the questions he works on. In the past, he has often studied existing social networks and looked at their effects. For instance: One study Eckles co-authored, examining the 2012 U.S. elections, found that get-out-the-vote messages work very well, especially when relayed via friends.
That kind of study takes the existence of the network as a given, though. Another kind of research question is, as Eckles puts it, “How do social networks form and evolve? And what are the consequences of these network structures?” His recent study about social networks expanding as people move around and change schools is one example of research that digs into the core life experiences underlying social networks.
“I’m excited about doing more on how these networks arise and what factors, including everything from personality to public transit, affect their formation,” Eckles says.
Understanding more about how social networks form gets at key questions about social life and civic structure. Suppose research shows how some people develop and maintain beneficial connections in life; it’s possible that those insights could be applied to programs helping people in more disadvantaged situations realize some of the same opportunities.
“We want to act on things,” Eckles says. “Sometimes people say, ‘We care about prediction.’ I would say, ‘We care about prediction under intervention.’ We want to predict what’s going to happen if we try different things.”
Ultimately, Eckles reflects, “Trying to reason about the origins and maintenance of social networks, and the effects of networks, is interesting substantively and methodologically. Networks are super-high-dimensional objects, even just a single person’s network and all its connections. You have to summarize it, so for instance we talk about weak ties or strong ties, but do we have the correct description? There are fascinating questions that require development, and I’m eager to keep working on them.”
