Summary of "Raj Chetty on Social Capital and Economic Mobility"
Summary of "Raj Chetty on Social Capital and Economic Mobility" Webinar
This webinar features Raj Chetty from Harvard University presenting his recent research on the role of social capital—specifically economic connectedness—in driving economic mobility in the United States. The discussion is framed by Marcus (likely a Princeton organizer or moderator), who introduces key concepts and contextualizes the research within broader economic inequality and mobility studies.
Main Ideas and Concepts
- Social Mobility vs. Inequality
- Social mobility is a dynamic measure of how individuals move between income or wealth brackets over time (e.g., poor to rich or vice versa).
- Inequality can be static (wealth snapshot) or dynamic (mobility).
- Resilience inequality: differences in individuals’ ability to bounce back from economic shocks, affecting their opportunities and long-term income/wealth.
- Social Capital and Economic Mobility
- Social capital broadly refers to the networks and connections people have.
- Raj Chetty’s work focuses on economic connectedness: the extent to which low-income individuals have friendships with high-income individuals.
- Other dimensions of social capital include cohesiveness (how tight-knit a community is) and civic engagement (volunteering, participation in organizations).
- Data and Methodology
- Utilizes anonymized Facebook friendship data (72 million U.S. users aged 25-44) combined with socioeconomic status (SES) proxies derived from zip code, education, phone type, etc.
- SES is ranked nationally by percentile within birth cohorts.
- Friendship networks are analyzed to measure:
- Economic connectedness (cross-class friendships)
- Cohesiveness (network clustering)
- Civic engagement (volunteering rates via Facebook groups)
- Validated Facebook data against traditional surveys (e.g., Add Health).
- Key Findings
- Economic connectedness is strongly correlated with upward mobility (correlation ~0.65).
- Other social capital measures (cohesiveness, civic engagement) show little or no correlation with economic mobility.
- Reverse causality (mobility causing connectedness) is unlikely because childhood friendships also predict mobility.
- Using a quasi-experimental “movers design,” growing up in counties with higher economic connectedness causally increases adult earnings for low-income children by about 20%.
- Economic connectedness explains much of the previously observed relationships between mobility and factors like income inequality and racial segregation.
- Increased economic connectedness benefits low-income kids without harming high-income kids’ outcomes, suggesting it is not a zero-sum game.
- Determinants of Economic Connectedness
- Two main drivers:
- Exposure: How much low-income individuals are physically/socially exposed to high-income individuals (e.g., school, neighborhood segregation).
- Friending bias: The tendency to not befriend high-income individuals even when exposed to them.
- Both exposure and friending bias equally contribute to social disconnection.
- Different social settings vary in exposure and friending bias:
- Low-income people make more friends in neighborhoods; high-income people make more friends in college.
- Religious and recreational groups show less friending bias.
- Friending bias is higher in larger schools and places with more tracking and diversity, posing challenges for integration efforts.
- Two main drivers:
- Policy Implications and Interventions
- Addressing social disconnection requires tackling both exposure (integration policies) and friending bias (facilitating cross-class interaction).
- Smaller group settings and deliberate mixing (e.g., Berkeley High School’s “houses” system) can reduce friending bias.
- Other interventions include prescribed seating, extracurricular activities, and programs connecting disadvantaged personal trainers with affluent clients.
- Released data (socialcapital.org" target="_blank" rel="noopener noreferrer">socialcapital.org) can help identify schools and communities with high friending bias or low economic connectedness to target interventions.
- Social capital and economic connectedness should be considered alongside traditional resource-based policies to improve upward mobility.
- Additional Notes
- The research is ongoing; questions remain about how online social platforms affect social capital and how COVID-19 has influenced connectedness.
- The importance of studying social capital as a complement to resources and incentives in economic policy is emphasized.
Methodology / Analytical Steps
- Measuring Social Capital
- Use Facebook data of friendships among 72 million U.S. users aged 25-44.
- Construct SES index via machine learning combining zip code, education, phone model, etc.
- Define economic connectedness as the share of high-SES friends that low-SES people have, normalized against a random friending benchmark.
- Measure cohesiveness via network clustering coefficients.
- Measure civic engagement via volunteering group participation.
- Testing Relationships
- Correlate social capital measures with upward mobility rates from tax data.
- Use childhood friendship networks and Instagram youth data to address reverse causality.
- Employ mover’s design with
Category
Educational