During the period 2000 to 2009, the Census bureau estimated that a net of about 2.5 million people moved out of the Northeast and another 1.8 million people left the Midwest. The beneficiaries of that huge out-migration were, of course, the South and the West. That meant that on average over the past decade a net of about 40,000 people a month left the Northeast and Midwest for the other two regions.
Between two-thirds and three-quarters of the people who moved from one region to another were under age 40. Since the bureau started gathering this data, young adults have always been more likely to move than older people who often put down roots and are reluctant to pull them up.
The result, however is that consumer markets in Northeastern and Midwestern states are generally aging faster than those in the other two regions. One indication of this is that nine of the 10 states where median age increased the most were in those two regions. The nation's most rapidly aging states were Maine, New Hampshire and Vermont, where the median rose an average of four years from 2000 to 2010, more than twice the 1.9 year increase for the nation.
Most consumer marketing, however, targets one or more age groups, not the median. So perhaps what matters more is what is happening to a key cohort of millennials age 25 to 34 where spending is likely to increase the most during this decade. By 2020 they will all be 35 to 44 and if recent history in any guide, will be spending at least an additional $10,000 per household per year or nearly $2 trillion more over the next 10 years.


