Socioeconomic Factors Associated with Declining Birth Rates in Los Angeles County Since 1990

BACKGROUND:  Birth rates in the United States have been at or below the “replacement rate” since 1972. In order to assess likely impacts of declining birth rates in Los Angeles County (LAC), this overview characterizes birth rate trends from 1990 to 2012, along with demographic, economic and behavioral factors that may be contributing to these trends.

METHODS:  Total Fertility Rate (TFR) and age-specific birth rate trends were calculated using numerators at five-year intervals based on a subset of 1.65 million births from women of childbearing ages (10-54 years) recorded in the Los Angeles County Birth Statistical Master File (BSMF) released by the California Department of Public Health. Intercensal population estimates derived from US Census data constituted the denominators. Economic data were obtained from the US Census’ American Community Survey and the Department of Finance.

RESULTS:  The TFR for LAC dropped precipitously from 1990 to 2010, from 2.7 to 1.8 births, falling below the replacement rate (2.1) and remaining just below that of both California and the US (1.9 each). During the same period, age-specific birth rates decreased for all maternal age groups between the ages of 15 to 34, but increased for women aged 35 to 44 years. The TFR fell for all major race/ethnicity groups in LAC, with only Hispanics/Latinos remaining above the sustainable replacement rate at 2.2 births per woman per year. Between 2006 and 2011, birth rates for mothers with educational attainment below a high school diploma decreased by more than half, from 131 to 62 per 1,000 women of childbearing age. Between 2005 and 2012, annual birth rates in LAC showed an inverse correlation to the percent of LAC residents who were unemployed. Finally, between 1990 and 2012, the mean age at first birth for all race/ethnicity groups in LAC increased by an average of 2.7 years (range 1.9-3.7).

CONCLUSIONS:  Since 1990, LAC has seen a dramatic drop in its total fertility rate similar to that for California (2.5 to 1.9) and strikingly steeper than that for the US (2.1 to 1.9). Multiple factors appear to be related to this decrease, including a steep drop in birth rates among younger women and those with less than a high school diploma. Economic factors and behavioral choices may also be playing a part. Policymakers’ recognition of these trends and their possible economic and health impacts on County residents are stressed.