From the abstract:
Union workers continue to receive higher wages than nonunion workers and have greater access to most employer-sponsored employee benefits; during the 2001–2011 period, the differences between union and nonunion benefit cost levels appear to have widened
Recent data from the Bureau of Labor Statistics (BLS) show that, on average, union workers receive larger wage increases than those of nonunion workers and generally earn higher wages and have greater access to most of the common employer-sponsored benefits as well. These trends appear to persist despite declining union membership. The National Compensation Survey (NCS) measures compensation levels and benefit provisions for many worker and industry characteristics. This article uses NCS data to examine some of the similarities and differences between union and nonunion compensation during the period from 2001 to 2011.