The UAB pays tribute to the academic career and economic research of Matthew O. Jackson

Rector Lafuente highlighted that, by awarding this honorary doctorate to Dr Jackson, “we wish to honour his decisive contribution to understanding how interpersonal relationships shape opportunities, mould behaviours, and influence both individual and collective outcomes”. The rector emphasised that Dr Jackson’s research reminds us “that individuals do not act in isolation; rather, we are part of a web of connections that often shape our decisions and possibilities”. He added that “This approach has enabled a richer and deeper understanding of the mechanisms that structure life in society, and it allows for the design of more effective public policies to advance toward a fairer, more cohesive, and more equitable society.” Rector Lafuente noted that Dr Jackson “has built a theoretical framework that provides a better understanding of significant phenomena—such as the persistence of inequalities, the transmission of behaviours and values, the diffusion of knowledge and innovation, and the capacity of societies to foster cohesion and promote social mobility”. The rector concluded by highlighting that Professor Jackson serves as “an excellent example of how knowledge advances through academic cooperation networks and the bonds of trust and friendship among researchers”.

Homophily and social inequality

“Receiving this distinction from the UAB is very special because of the strong ties that bind me to it,” Jackson said at the start of his lecture. “A recognition like this gains even more value when it comes from a community I deeply appreciate and admire.”

The Stanford professor presented scientific evidence demonstrating how homophily—the human tendency to associate with people from similar backgrounds—and a lack of "economic connectedness" are key factors in the persistence of inequality and the absence of social mobility. According to his research, access to friendship networks that span different socioeconomic levels is the decisive factor enabling young people from less affluent families to thrive. Such networks not only provide job opportunities and referrals, but also convey crucial information, serve as sources of inspiration, and establish behavioural norms. For Jackson, the link between friendships formed during childhood and youth and future success is direct and causal: "Taken together, these friendships matter more than the socioeconomic status of one's parents", he stated.

A global phenomenon that explains inequalities

Analysis carried out in various settings—from massive social media data in the United States to rural communities in 46 countries around the world—shows that this is not a phenomenon exclusive to major economic powers, but a deep-seated social dynamic.  It also revealed that the lack of connection between social classes occurs for two main reasons: a lack of physical exposure (segregation in neighbourhoods or schools) and affinity bias (friending bias), whereby we tend to seek out friends who are similar to us even when we have the opportunity to interact with more diverse profiles.

New public policies

Jackson proposed reorienting the design of public and educational interventions. On the one hand, he emphasised the need to foster genuine spaces for coexistence: “The educational curriculum should be designed so that there is sustained contact and deep interaction that fosters friendships.” On the other hand, he argued for the need to join resources rather than scatter them: “Distributing interventions evenly may be less effective than concentrating them in areas where a sufficiently large impact can be generated to trigger a social network multiplier and a discontinuous change in behaviours.” The professor concluded his lecture by recalling the relevance of these findings for the future of political and economic design.

A leader in his field

In his presentation of the merits of the honorary doctorate recipient, his sponsor, Xavier Vilà, highlighted Professor Jackson’s scientific contribution. Vilà stated that “by combining rigorous mathematical formulation with empirical observation, Jackson developed the theoretical foundations that led to his widespread recognition as the primary architect of research into the role of networks in economics and the social sciences”.