This new theoretical framework shows that if the objective of regulators is to conserve resources by reviewing only those mergers most likely to harm workers, while ensuring that workers are unharmed by permitted mergers, then the more stringent 1982 guidelines are more effective than the more lenient 2010 guidelines.

Driven by the sizable shift in sales and employment from the relatively concentrated manufacturing sector to the relatively unconcentrated service sector, local concentration in sales has increased in parallel to national sales concentration, while local concentration in employment has declined, despite rising at the national level.

The pervasiveness of employer-provided healthcare in the United States contributes to labor market inequality; under an alternative scenario where healthcare is funded by a payroll tax on firms, the college-wage premium would be 11% lower. If healthcare costs had grown at the rate of other countries, inequality would have grown less as well.