Characterizing social network homophily and residential mobility through analysis of call detail records
Sustainable Growth


Cities are engines of productivity, diversity, and economic growth, but while the largest cities have disproportionately higher incomes, they also tend to have disproportionately higher housing costs which often push low/middle income residents away from centres of economic activity, thus leading to higher income inequality. 
This relationship between inequality and city size underscores the importance of social capital to inclusive growth. People regularly access economic opportunities through the capacity of their collective social networks, and then often rely on core social networks in times of difficulty. 

Telecommunications data demonstrates that people in highly prosperous areas have on average more spatially diverse communication patterns—they have repeated contacts with individuals in many separate locations—whereas people in less prosperous areas tend to limit their communications to spatially redundant and closely-knit cores. As cities continue to grow, we can expect that city dynamics will depend heavily on residential mobility.


This project will explore the relationship between social networks, socioeconomic class, and residential mobility, investigating how social network properties tend to influence one’s propensity to move, the effect of moving on one’s social network, and how these relationships are facilitated by income.
The second portion of our study examines what factors influence the stratification of communication patterns (social networks) along socioeconomic lines. In particular, we will examine whether and to what extent this social network stratification is influenced by residential socioeconomic segregation and/or socioeconomically stratified urban travel patterns.

In our study, we will use Call Detail Record (CDR) to approach the following questions:

  1. Does living in a socioeconomically less isolated area (e.g. closer to neighbourhoods of different socioeconomic class) lead to having a more socioeconomically diverse social network? Does living in a less socioeconomically isolated area make you more likely to interact with different socioeconomic classes?
  2. Is having a more socioeconomically integrated/diverse travel patterns linked with having a more socioeconomically diverse social network? That is, does traveling to areas of varying socioeconomic class increase your propensity to interact with different socioeconomic class?
  3. How do these two relationships vary across different income levels?

In particular, we will study these relationships using data from Colombia, and pay special attention to the unique factors driving urbanization, residential mobility, and class stratification in Colombian cities. Moreover, our aims will be duly scientific and policy-oriented, with an emphasis on generating large-scale data that has importance to current urban policy issues in Colombia.