Last month Smart Politics examined the political impact on the state of Minnesota should it lose one U.S. House seat as projected by many analysts, including a recent report issued by Election Data Services.
Earlier this week, the Centers for Disease Control and Prevention released new data detailing the teenage (15 to 19 year old) birth rates for each of the 50 states for 2006 (the most recent year for which data is available). While Minnesota has the 22nd highest overall birth rate among the 50 states, it only has the 41st highest rate among teenage mothers - at 27.9 per 1,000 women in that age group. That rate is 33.4 percent below the national average of 41.9 births per 1,000 teenage girls.
As it turns out, two-thirds of the U.S. House seats projected to be added to states during reapportionment in 2012, are in states with the Top 10 highest teenage birth rates, including Texas (+4 seats, 63.1 births per 1,000 teenage girls), Arizona (+2 seats, 62.0 per 1,000), Nevada (+1 seat, 55.8 per 1,000), and Georgia (+1 seat, 54.2 per 1,000).
Not surprisingly, in addition to Minnesota, several other states with low teenage birth rates are among those projected to lose a U.S. House seat, including Massachusetts (-1 seat, 21.3 births per 1,000 teenage girls), New Jersey (-1 seat, 24.9 per 1,000), New York (-1 seat, 25.7 per 1,000), Pennsylvania (-1 seat, 31.0 per 1,000), Iowa (-1 seat, 32.9 per 1,000), and Michigan (-1 seat, 33.8per 1,000).
Just how strong is this association?
Smart Politics conducted a bivariate correlation of the teenage birth rate for each state and its projected gain, loss, or no change in the number of U.S. House seats, and found these variables are positively related (.544, significant at the .01 level). In other words, greater increases in teenage birth rates are associated with greater increases in representation in Congress.
This, of course, makes sense: higher birth rates among any segment of childbearing women means a greater population base for that state, which drives the census numbers in a state's favor, and thus helps to insulate it from losing a seat (and, perhaps, to help it to gain a seat) in Congress.
But not all states are experiencing both a surge in teenage and general birth rates. Utah, for example has the highest overall birth rate in the nation, at 21.0 per 1,000 women, but just the 33rd highest teenage birth rate, at 34.0 per 1,000 teenage girls. Florida, which is another state projected to gain a seat in 2012, has only the 38th highest general birth rate (13.1), but has the 17th highest rate among teenagers (45.2).
The discrepancy in state rankings in Minnesota between its teenage birth rate (22nd) and overall birth rate (41st) is the seventh largest in the country, behind Utah, West Virginia, Idaho, Nebraska, Florida, and Kentucky.
Smart Politics also conducted a linear regression analysis, using statewide teenage birth rates as the independent variable and projected change in reapportionment as the dependent variable. The results show an increase of 1 birth per 1,000 teenage girls in a state causes an increase of about one-fifth (0.17) of a seat in Congress. Twenty-two percent (R Square = .218) of the variation in reapportionment in this model is explained by changes in the teenage birth rate (the model as a whole is highly significant, at the .001 level).
Of course, there are several other factors other than the birth rate (among teenagers or otherwise) that contribute to population changes within a state, such as economic development and the ability to attract jobs and immigrant populations. The economic stagnation in industrial Midwestern states such as Michigan and Ohio is seen as a leading reason for the expected loss of U.S. House seats in those states. The mass exodus after Hurricanes Katrina and Rita will also see a likely loss of a seat in the state of Louisiana.
U.S. Census data also reveals that the teenage birth rate itself is highly correlated to the percentage of minorities (.439, significant at the .01 level) and Hispanics (.293, significant at the .05 level) residing in a state. The new CDC birth rate numbers show that 8 of the 12 projected new seats will be distributed to 4 of the 6 states in the nation with a 20+ percent Hispanic population (Texas, Arizona, Nevada, and Florida). Minnesota ranks just tied for 35th among the states in percentage of Hispanic population and 39th among racial minorities in general. Iowa, which is also projected to lose a seat, ranks just 35th and 46th respectively.