No state or city shall restrict people’s movement.

By David Schleicher, a professor at Yale Law School. From The New York Times.

"America needs to get moving again. Over the past 40 years, Americans have moved from one state or city to another less and less frequently. This lack of mobility — and the lack of population growth in highly productive cities and regions — substantially harms the economy.

Once, local economic booms created boomtowns, but they no longer do. Chicago grew from a city of 30,000 people in 1850 to 1 million in 1890 to 3.3 million in 1930; Silicon Valley’s population has increased only slightly since the rise of the tech sector in the 1980s. Low population mobility makes economic redistribution less effective, since poor people are less likely to be in the same states and cities as rich taxpayers. It also makes the job of the Federal Reserve harder, since setting interest rates is challenging when there are varied levels of unemployment and inflation.

While there are several explanations for declining mobility, one is that state and local laws clearly make it harder for people to move toward opportunity. Zoning regulations limit housing construction in many wealthy cities and regions, raising housing costs and limiting in-migration for those who don’t already have high salaries to take advantage of those strong economies. Land use regulations in the most productive regions have reduced economic output by 36 percent between 1964 and 2009. Occupational licensing regulations cover 25 percent of workers and limit the ability of people to move between states because their licenses do not travel.

The Constitution, through the dormant commerce clause, already bars state laws that discriminate against interstate trade. A new constitutional amendment could bar state and local laws that have the effect of limiting interstate population mobility, freeing the national economy from protectionist and not-in-my-backyard state and local legislation. Such an amendment could be used to invalidate unreasonable land use regulations — such as excessive minimum lot size rules and unjustified density limits — and labor regulations that discriminate in their effects against out-of-state workers."