The Thanksgiving break is coming up; half of the office is already acting like they're on vacation; why not spend your day messing around with this awesome map of American migration! Forbes grinds up IRS data into an interactive map that shows county by county how many people moved hither and thither from 2005 to 2009.
As you can see on the map here, Minnehaha County shows a pattern of drawing lots of migrants from adjacent rural counties while other migrants jump off to farther flung metro areas. That matches a trend state demographer Mike McCurry mentioned a couple weeks ago.
Lake County's numbers show out-migration beating in-migration in four of five years. Only in 2009 did we gain more people than we lost. The map also shows a generally tight sphere of mobility: almost all of our moves in and out connect us with adjacent counties, with a little stretch to Lincoln County. Two notable exceptions to that lack of geographical reach: an outflux from Lake County to Hennepin County, MN, in 2008, and two influxes from Polk County, TX, in 2008 and 2009. Hmmm... Polk County... could it be that MyDakotaAddress.com did some good advertising there and drew a surge of RVers from that locale?
Lawrence County shows a little more reach beyond the neighboring counties, with migrants coming and going regularly to and from the Pierre and Sioux Falls area, as well as the Phoenix metroplex in Maricopa County. One might think that's a lot of snowbirds moving back and forth, but except for in 2006, the per capita income of those migrants, both in and out, is lower than than per-capita income of the Spearfishians sticking around. Hmm... migrant labor?
Make sure the boss isn't watching, then play with the map, and see what demographic trends you can spot!