What’s Behind States’ Population Growth?

Fifteen states experienced significant population increases last year. New Census estimates on migration trends and birth rates provide a glimpse into what's driving each state's growth. View data for your state.
by | February 4, 2014 AT 9:00 AM

While most states don’t experience significant population shifts over short periods, some added notable tallies of residents last year. In all, 15 states and the District of Columbia recorded population increases exceeding 1 percent.

The  Census Bureau's most recent estimates provide a glimpse of what’s behind annual population changes in each state. Some see large numbers of residents move in from other states, while others benefit more from births.

North Dakota again registered the largest increase in terms of percentage change, jumping 3.1 percent between July 2012 any July 2013. The state’s growth – largely fueled by an oil boom – hasn’t yet slowed down, with its net domestic migration rate nearly doubling from 2012.

After North Dakota, the District of Columbia (+2.1 percent), Utah (+1.6 percent) and Colorado (+1.5 percent) saw the largest gains over the 12-month period.

The Census Bureau estimates each state’s population as of July using birth records, tax filings, Medicare enrollment and other data sources.

Here’s an overview of some of the demographic shifts driving population increases in the fastest-growing states. (View complete 2013 data for all states here)

Americans Moving to New States

Along with rapidly expanding North Dakota and D.C., Colorado has emerged as a magnet for new residents.

The state recorded high domestic migration rates in recent years, but last year, its rate jumped to third in the nation at 6.9 per 1,000 residents.

Elizabeth Garner, Colorado’s state demographer, said the state’s economy helped drive population gains.

Colorado has benefited from an expanding energy sector, but not near to the extent North Dakota or Texas has. Last year, its jobs surpassed pre-recession levels.

Many of those moving in, Garner said, fall in the age 25 to 34 bracket, establishing residency in the Denver, Colorado Springs or Greeley metro areas. For a long time, some of these gains were offset by retirees moving out of the state. This gradually changed, though, as net domestic migration for the 65-and-over population is now nearly positive, Garner reports.

A few less populous states also saw domestic migration rates climb in recent years, particularly South Carolina, South Dakota and Montana.

The following table shows states adding residents from other states at the greatest rates:

State Net Domestic Migration 2013 Rate per 1,000 pop. 2012 Rate per 1,000 pop. 2011 Rate per 1,000 pop.
North Dakota +16,961 23.8 15.6 8.9
District of Columbia +6,319 9.9 10.0 11.4
Colorado +36,284 6.9 5.5 5.3
South Carolina +29,324 6.2 5.6 3.2
South Dakota +4,762 5.7 4.9 2.3
Montana +5,467 5.4 3.7 3.3
Florida +91,484 4.7 5.2 5.6
Nevada +12,854 4.6 5.3 -2.8
Wyoming +2,616 4.5 9.8 -0.5
Texas +113,528 4.3 5.5 4.6
Source: Census Bureau, Population Estimates Program

Alaska (-5.5), New York (-5.3), Illinois (-5.2) and New Jersey (-5.1) round out the bottom of the list. In terms of raw totals, Texas and Florida continue to welcome the most residents.

For a more in-depth look at types of individuals moving to each state, please see our analysis of 2012 data.

International Migration Lifts State Totals

The Census Bureau also estimates international migration, which includes movement among the foreign born, U.S. natives and members of the military.

For the second consecutive year, Hawaii posted the highest international migration rate of any state. There weren't any surprises here, as Hawaii and coastal states regularly add large numbers of residents from overseas.

Just behind Hawaii was New Jersey, with a net international migration of 5.2 residents per 1,000 population. Both the Garden State and neighboring New York experienced slight upticks in recent years.

Over the 12-month period, the country saw a total net international migration of 866,000 people.

Here’s a map showing states registering the highest 2013 net international migration rates (not raw totals):

Note: Please zoom out to view Alaska and Hawaii

Newborns Boost Younger States

Newborns greatly push up some states' population counts, while deaths actually exceed births in a select few others.

States with younger residents (as measured by median age) tally the largest year-over-year natural increases, or births minus deaths.

Utah, the youngest state with a median age of 29, has recorded the nation’s highest birth rate the past several years. Between July 2012 and last summer, an estimated 51,000 babies were born and less than 15,000 residents died statewide.

Births rates also vary among racial and ethnic groups. The next-highest gains were in Alaska and Texas, which benefits from a large population of Hispanics and their above-average fertility rates.

Maine, home to the nation’s oldest residents, and West Virginia were the only states where deaths exceeded births.

The following states recorded the highest overall rates for natural population change last year:

State Natural Change Rate per 1,000 pop. Births Deaths
Utah 12.5 50,840 14,875
Alaska 10.2 11,610 4,113
Texas 7.9 381,897 173,852
District of Columbia 6.9 9,589 5,151
Idaho 6.8 22,187 11,250
California 6.6 503,634 250,567
South Dakota 6.3 11,992 6,736
Colorado 6.2 65,831 33,159
Nebraska 6.1 25,703 14,385
North Dakota 6.0 10,028 5,754
Source: Census Bureau, Population Estimates Program

Review 2013 estimates for all 50 states and the District of Columbia