Accounting for the Recent Decline in the NAIRU

This paper confirms that the unemployment rate associated with stable inflation, the so-called "NAIRU," probably has declined in recent years, after having risen sharply during the late 1970s and early 1980s. Although a demographic shift toward a less experienced workforce and an unexpected slowdown in trend productivity growth are able to explain the earlier rise in the NAIRU, a reversal of these effects does not adequately explain the timing of the apparent decline in the NAIRU during the 1990s. I propose that an additional element needs to be incorporated into the assessment. I argue that the degree of integration of regional labor markets across the United States has accelerated over the recent past, leading to a greater degree of synchronization in the pattern of regional labor market conditions and regional business-cycle conditions. I provide evidence of this greater synchronization, and suggest that it may have led to a drift downward in the NAIRU.