An influx of new residents can provide local governments with a substantial boost, whether they’re adding to tax rolls or spending their dollars supporting local businesses.

Last week, the Internal Revenue Service (IRS) released long-awaited migration data shedding light on migration patterns for counties and states. New data for 2011 and 2012 includes total incomes for those who moved, helping to approximate wealth gained or lost and its potential impact on local budgets.

A range of factors influence a person’s decision to move. Most often, employment considerations largely dictate where people opt to relocate. Others, depending on their circumstances, decide more based on family-related reasons. An area’s amenities, taxes and educational opportunities also all typically play some role in decisions to move.

Wealthier residents are often tied to specific job locations, such as a corporate headquarters or employment center for a particular industry. So, their occupations may drive decisions somewhat more than other workers. Technology, however, is enabling more employees to work remotely, so job-related considerations may not carry as much weight in moving decisions as they had in the past, said Steve Murdock, a former U.S. Census Bureau director who now teaches at Rice University.

The independently wealthy or retired, on the other hand, typically give greater consideration to regional amenities or quality of health services. But as retirees age and their health deteriorates, they may require more services or move back to where they came from. As a result, Murdock said, these areas that are attracting large numbers of older, wealthier residents need to be replenished with new retirees each year.

“High incomes are both produced by migration and allow for migration,” Murdock said.

The IRS reports numbers of actual tax returns, which can be used to approximate households moving to and from each county. Adjusted gross income (AGI) figures serve as a proxy for total household incomes. One way to assess total wealth gained or lost is to compute a net migration AGI, or total AGI for in-migrants minus AGI for outmigrants. The following table lists this measure for counties with 1,000 or more new residents:

SOURCE: Governing calculations of 2011-2012 IRS migration data. Data shown for counties with at least 1,000 new returns.

Migration patterns show longtime retirement hotspots in parts of Florida and the southwestern United States are attracting the most wealth overall.

One locality that’s experienced rapid growth in recent years -- both in terms of wealth and total population -- is Loudoun County, Va. The county benefits from a variety of mixed-used developments, agriculture businesses and proximity to jobs in and around the Washington, D.C., region. County Budget Officer Erin McLellan said migration, which accounts for roughly two-thirds of recent population growth, has helped grow the county’s property tax base. Between 2011 and 2015, the assessed value of residential property increased by more than 28 percent, driven in part by households with ample incomes and good employment prospects, she said.

Many counties recording the largest losses in migration wealth serve as hubs for immigrants. Urban areas have historically relied on foreign migration to offset domestic migration losses as residents leave cities. Of course, it’s worth noting that the IRS data doesn't reflect individuals who don't file tax returns, which could include undocumented immigrants as well.

The IRS bases its data on address changes reported on individual income tax returns over consecutive years. New data are not directly comparable to prior years, in part because of a few recent methodological improvements. The IRS reports that its migration figures are now based off an entire year of data, instead of a partial year, and a different matching process was used that yielded greater numbers of matching year-to-year returns.

The IRS previously canceled the migration data program in 2012 but later reversed the decision after it faced public pressure to restore it.

County Migration Data

County migration data tool page

IRS methodology

Select your county to view its IRS migration data for 2011-2012: