The growing importance of family and community

"This study presents evidence that the correlation in brothers' earnings has risen in recent decades. We use two distinct cohorts of young men from the National Longitudinal Surveys and estimate that the correlation in earnings between brothers rose from 0.26 to 0.45. This suggests that family and community influences shared by siblings have become increasingly important in determining economic outcomes. We find that neither the correlation in years of schooling nor the rising return to schooling accounts for this increase. We also argue that the PSID is not an appropriate dataset for analyzing changes over time because of its sampling design, small sample of siblings, and high attrition rate"--Federal Reserve Bank of Chicago web site.