Adam Davidson's latest NYT Magazine column is a must read, and it highlights one of the topics we love to keep an eye on at The Watch: mobility. Historically, a high level of economic mobility in the U.S. has often meant a lot of geographic mobility. But today? Not so much interstate migration, as this NYT graphic shows:

Davidson points out that mobility requires industries that are successful and creating jobs to pull people from one state to another. And the industries that have that pull today are looking for workers with particular skills.
Part of the problem is that the country’s largest industries are in decline. In the past, it was perfectly clear where young people should go for work (Chicago in the 1870s, Detroit in the 1910s, Houston in the 1970s) and, more or less, what they’d be doing when they got there (killing steer, building cars, selling oil). And these industries were large enough to offer jobs to each class of worker, from unskilled laborer to manager or engineer. Today, the few bright spots in our economy are relatively small (though some promise future growth) and decentralized. There are great jobs in Silicon Valley, in the biotech research capitals of Boston and Raleigh-Durham and in advanced manufacturing plants along the southern I-85 corridor. These companies recruit all over the country and the globe for workers with specific abilities. (You don’t need to be the next Mark Zuckerberg to get a job in one of the microhubs, by the way. But you will almost certainly need at least a B.A. in computer science or a year or two at a technical school.) This newer, select job market is national, and it offers members of the mobile class competitive salaries and higher bargaining power.
Many members of the immobile class, on the other hand, live in the America of the grim headlines. If you have no specialized skills, there’s little reason to uproot to another state and be the last in line for a low-paying job at a new auto plant or a burgeoning green-energy cluster. The surprise in the census data, however, is that the immobile work force is not limited to unskilled workers. In fact, many have a college degree.
This column has sparked an ongoing online conversation at the Planet Money blog. Read Davidson's column here. And then go to responses from Brookings demographer William Frey, here, and Northwestern economist Joseph Ferrie, here.