The District has enjoyed strong population growth in the past 10 years even as growth appears to have slowed in 2014. What accounts for this rapid growth? In this blog we examine one of the components of population change–births. We will discuss the other components–migration and deaths–in subsequent blogs.
According to recent statistics published in the National Vital Statistics Report “Births: Final Data for 2013”, the District’s birth rate, defined as births per 1000 population, was sixth highest in the Nation in 2013. There were 9,338 births in the District which measured against a population of approximately 645,000 translates into a birth rate of 14.4 births per 1000 residents. This compares to an average of 12.4 births per 1000 in the Nation. Ten years ago in 2003 the District’s birth rate was 13.5 compared to 14.1 for the nation.
Looking at the statistics in more detail reveals interesting differences in the age of women when births occur in the District compared to the Nation.
- For ages 35 and over, the District ranked first in terms of birth rates. The top 10 States were largely concentrated in the Northeast. Connecticut, Massachusetts, New York and New Jersey were consistently ranked in the top 10 for ages 35 and over.
- Alaska, Hawaii, Maryland and California also had high birth rates among women in these age brackets.
- For ages 40 and over the District’s birth rate was twice the national average.
- For the nation overall there has been a secular increase in births occurring later in lives of women. The rate for women aged 40 to 44, has doubled from approximately 5 percent in 1990 to over 10 percent in 2013.
- We do not have long-term historical data for this age group in the District but in 2008 the birth rate was 16 percent in the District compared to 9.8 percent in the U.S. In recent years, the growth in the birth rate for this age group has far exceeded the national average.
In contrast for adult women aged under 35, the opposite occurred and the District ranked almost last for this group.
- Interestingly the District’s ranking dropped rapidly for the cohort aged 30-34 while several Northeastern States: Connecticut, Massachusetts and New Jersey were still ranked in the top 10.
- It is important to note that the District also ranked highest in the nation for births among non- adult aged women even though birth rates have been declining for this group over the past 20 years. For women aged 15-17 the birth rate was 23.9, almost twice the national average, and for those aged 10-14 the 1.6 birth rate was more than twice the national average.
Various factors are often cited to explain differences in birth rates among age groups of women. These factors include, among others, socio-economic, ethnic, educational attainment, and cultural factors. A body of economic and demographic research has recently emerged examining how high housing costs may also affect and delay household formation decisions. A study by William A.V. Clark for the California Center for Population Research, finds that high housing costs can delay the first birth by as much as three to four years. As noted in the study, the relationships between these factors and causation effects and directions can be very complex. For instance do higher housing costs cause people to get more advanced degrees and therefore delay household formation in order to be able to afford housing, or is the direction of causation the opposite way? All this suggests that the effects of housing prices on demographics and ultimately tax revenues need to be watched very closely.
What exactly is the data? Birth rate data is from Martin JA, Hamilton BE, Osterman MJK, et al. Births: Final data for 2013. National vital statistics reports; vol 64 no 1. Hyattsville, MD: National Center for Health Statistics. 2015. The report can be found here. Evidence on the effects of housing prices and household formation is from William A.V. Clark, and can be found here.
Bob Zuraski contributed to this post