Ecological Analysis of Teen Birth Rates: Association with Community Income and Income Inequality

Objectives : To examine whether per capita income and income inequality are independently associated with teen birth rate in populous U.S. counties. Methods : This study used 1990 U.S. Census data and National Center for Health Statistics birth data. Income inequality was measured with the 90:10 ratio, a ratio of percent of cumulative income held by the richest and poorest population deciles. Linear regression and analysis of variance were used to assess associations between county-level average income, income inequality, and teen birth rates among counties with population greater than 100,000. Results : Among teens aged 15–17, income inequality and per capita income were independently associated with birth rate; the mean birth rate was 54 per 1,000 in counties with low income and high income inequality, and 19 per 1,000 in counties with high income and low inequality. Among older teens (aged 18–19) only per capita income was significantly associated with birth rate. Conclusions : Although teen childbearing is the result of individual behaviors, these findings suggest that community-level factors such as income and income inequality may contribute significantly to differences in teen birth rates.