Yes, Occupational Licensing is Making Us Less of an OCA

From a new working paper by Janna E. Johnson, Morris M. Kleiner:

Occupational licensure, one of the most significant labor market regulations in the United States, may restrict the interstate movement of workers. We analyze the interstate migration of 22 licensed occupations. Using an empirical strategy that controls for unobservable characteristics that drive long-distance moves, we find that the between-state migration rate for individuals in occupations with state-specific licensing exam requirements is 36 percent lower relative to members of other occupations. Members of licensed occupations with national licensing exams show no evidence of limited interstate migration.

So why does the decline in labor mobility matter for the U.S. economy? To answer this question, recall that the Fed is doing a one-size-fits-all monetary policy for fifty different state economies. That is, the Fed is applying the same monetary conditions to states that often have very different economies, both structurally and cyclically. For example, Michigan and Texas have had very different trajectories for their economies. Does it really makes sense for them both to get the same monetary policy?  

According to the OCA, the answer is yes under certain circumstances. The OCA says it makes sense for regional economies to share a common monetary policy if they (1) share similar business cycles or (2) have in place economic shock absorbers such as fiscal transfers, labor mobility, and flexible prices. If (1) is true then a one-size-fits-all monetary policy is obviously reasonable. If (2) is true a regional economy can be on a different business cycle than the rest of currency union and still do okay inside it. The shock absorbers ease the pain of a central bank applying the wrong monetary policy to the regional economy.  

For example, assume Michigan is in a slump and the Fed tightens because the rest of the U.S. economy is overheating. Michigan can cope with the tightening via fiscal transfers (e.g. unemployment insurance), labor mobility (e.g. people leave Michigan for Texas), and flexible prices (workers take a pay cut and are rehired).  

To be clear, a regional economy is not making a discrete choice between (1) and (2) but more of a trade off between them. Michigan, for example, can afford to have its economy a little less correlated with the U.S. economy if its shock absorbers are growing and vice versa. There is a continuum of trade offs that constitutes a threshold where it makes sense for a regional economy to be a part of a currency union. That threshold is the OCA frontier in the figure below: 

Circling back to the original OCA question, the decline in labor mobility documented above matters because it means that certain regions in the United States are becoming less resilient to shocks. This is especially poignant given the findings in Blanchard and Katz (1992) that interstate labor mobility has been the main shock absorber for regional shocks. Consequently, monetary policy shocks may prove to be more painful than before for some states. Unless increased fiscal transfers and price flexibility make up for the decline in labor mobility, the implication is clear: the U.S. is gradually moving away from being an OCA.