Methodology

Where the data comes from

The data used in this report comes from the Internal Revenue Service's County to County Migration Tables.

Each year, the IRS tracks social security numbers given on tax returns. If a given social security number comes from a different county than the year before, that person, and all the dependents listed on the return are considered migrants.

The IRS provides MARC with:

• the number of returns (households)
• the number of exemptions (population)
• total income

Due to disclosure policies, only significant migrations (at least 10 individuals moving from county to county) are included. For example, if County X saw 9 residents move to County Y we would not know the county of origin. Those migrants would be combined in a “other migration” category. However, if 10 residents moved from County Y to County X, the IRS data would show the originating county.

Another limitation is the fact that individual filers one year may file may be the secondary filer on a joint file due to a marriage. The data also captures only 95 to 98 percent of all returns filed during any given year mostly because of late filings. Despite the fact that this data can not account for every migrant into and out of the region, it still provides us with the best estimate of migration flows. These flows can tell us a lot about the Kansas City area. For starters, it tells us that Kansas City remains a net in-migration metro. More people move into the area than leave it. This would indicate that the region is doing a good job of providing opportunity for its new and existing residents.

Total Migration Summary

Between 1993 and 2004, the Kansas City Area had 591,283 out-migrants and 645,216 in-migrants for a net in-flow of just under 54,000 new residents.

This table breaks those numbers down further by specified county (counties that had at least 10 county to county migrants in a given year), other county (the sum migrants from counties that had fewer than 10 migrants in a given year), and foreign.

In addition to these external migrants, there were 524,899 migrants who moved from one county to another within the Kansas City area.