Good urban planning can dissolve the income inequalities encoded in friendship networks

Growing inequality is a global problem. In a new study published in the prestigious journal Nature Communications, researchers from Corvinus University, ELKH, ELTE, CEU and the International Business School rely on domestic data to demonstrate that urban planning can have a decisive impact on our social networks, and through this, inequalities. 

“Increasing income inequality is encoded in our social relationships.” – says Balázs Lengyel, researcher at ELKH and Corvinus University, corresponding author of the study. “We make friends with similar people, usually by knowing our friend’s friend. These are the basic characteristics of the development of social relations, which can lead to the formation of segregates in large social networks, for example in the network of connections of a city. In most societies, income status is an important similarity factor for friendships, so the poor are segregated from the rich in friendship networks. This may result in a further increase in inequality, as the information and opportunities necessary for prosperity are difficult to get from the rich to the poor.” 

The researchers find indirect evidence of this connection using anonymous data from the iWiW online social network. It is shown that income inequality grew more between 2011 and 2016 in Hungarian cities where the network of connections was segregated and where income inequality was also high in 2011.  

What can be behind the segregation of cities’ connection networks? According to the results of the study, long distances within cities, the concentration of services in the center, and physical barriers in the city, such as railways, rivers or highways, all make encounters difficult and increase network segregation. 

Urban planning can play a role in reducing network segregation. Although friendships cannot be shaped by regulation, the services available in the city and the elimination of physical barriers can create opportunities for meetings and interactions. According to the research, these can lead to the reduction of inequalities in the long term. 

The study is freely available at https://www.nature.com/articles/s41467-021-21465-0.