Win some, lose some: Expert provides reapportionment projections

But she also cautions that there are likely to be plenty of surprises.

According to Lisa Neidert, data services manager at the U-M Institute for Social Research (ISR) Population Studies Center, the most likely state winners -- based on July 2009 population estimates from the Census Bureau -- are Texas (3 seats), and Arizona, Florida, Georgia, Nevada, South Carolina, Utah, and Washington, each likely to pick up one seat in the U.S. House of Representatives.

Neidert expects state losers to be Ohio (2 seats), and Illinois, Iowa, Louisiana, Massachusetts, Michigan, New Jersey, New York, and Pennsylvania -- each likely to lose one seat.

Neidert used an online apportionment calculator to project how changes in state populations would be reflected in the apportionment of House seats for 2010 as compared to 2000. Her analyses also identify which states are most at risk for losing or gaining Congressional seats after factoring in recent population changes.

To identify surprise winners and losers, Neidert compares several measures of state population growth in 2008-2009.

"One obvious weakness in using pre-census population estimates is that states vary in their population growth, and the estimates leave out the last 9 months of growth, from July 1, 2009 through April 1, 2010," Neidert said. However, this did not change the projections much, but that does not mean she expects her projections will be spot on. She says that the population estimates could be off a bit just like they were 10 years ago. And if these deviations vary by state, it can change the winners and losers in the apportionment battles.

Neidert identifies four factors that could affect population estimates. "The dramatic slowdown in both international and internal migration with the economic downturn and housing collapse could have a positive benefit to states in the Northeast and Midwest that have been donor states," Neidert said. "And the impact on states in the Sunbelt or the West could be negative, with not as many inmigrants."

The increase in home foreclosures could also affect the population counts of states with high foreclosure rates, such as Arizona, Nevada, Florida, and Michigan. "Doubled-up households -- which have increased 11.6 percent between 2008 and 2009 according to the March Current Population Survey -- may not have been counted as well in the self-enumerated census," she said.

A third factor is the difficulty of estimating the Hispanic population, which is roughly 15 percent of the U.S. population, partly because of the undocumented population. The political posturing of whether or not to include non-citizens in the 2010 census and the new Arizona immigration law might have had an effect on the participation rate of Hispanics," Neidert said. "This could hurt any state with a high proportion of Hispanic residents.

Lastly, Neidert believes that the lingering effects of natural disasters, including Hurricane Katrina and the Haitian earthquake, might have an impact on population projections for Louisiana, and for New York and Florida, where Haitian refugees have mainly been settling.

"Expect the unexpected," in congressional reapportionment, Neidert concludes.

To access the online apportionment calculator and projections, visit http://www.psc.isr.umich.edu/dis/census/apportion_estimates.html