Newly released Bureau of Labor Statistics data on union membership trends show that union membership as a share of overall employment held steady at 10.7 percent in 2017, with essentially stable membership rates in both the private (6.4 or 6.5 percent) and public (34.4 percent) sectors.

Union membership gains among men offset continued losses among women last year. But, it is important to view these different trends by gender within historical context: union membership in 2017 was roughly equivalent among men (11.4 percent) as women (10.0 percent), compared to 1979 when men were more than twice as likely as women to be union members and comprised 69 percent of union members.

It is difficult to use one year changes in union membership trends to assess underlying dynamics. For one, the small samples involved for particular subgroups produce year-to-year volatility that should not be mistaken for a trend. Second, any change in union density can result from many different factors including the pattern of overall employment growth (whether sectors or occupations that are more heavily union grow faster or slower than average), the success or failure of union organizing drives, the scale of union organizing, changes in workers’ desire for union membership (i.e., demand for collective bargaining), and other factors. An understanding of the dynamics of union membership and representation requires a long-term analysis of detailed trends.

Nevertheless, it is worth squeezing out what is plausibly interesting in the most recent data:

• Union membership (according to the BLS release) rose by 262,000 in 2017, more than the 173,000 additional workers covered by a collective bargaining agreement (hereafter referred to as “coverage”). See Table 1 (which relies on tabulations of the underlying survey data because BLS does not provide gender breakdowns within sectors). The greater growth in union membership than coverage was driven by developments in the private sector where membership growth was triple (164,000) that of the growth of coverage (53,000), centered in professional and service occupations.

• Union membership became more common among men: some 32 percent of the net increase in male employment in 2017 went to men who were union members, leading union membership to rise from 11.2 to 11.4 percent of all male employment. Growth of union membership for men was strong in both the public and private sectors and for Hispanic and for non-Hispanic white men.
• Correspondingly, union membership dipped slightly among women because women’s union membership did not rise in the private sector although employment overall did rise—private sector employment growth for women was concentrated in nonunion sectors. Union membership growth, however, was strong among Hispanic women.

• Union membership grew in manufacturing despite an overall decline in manufacturing employment. Union membership was also strong in the wholesale and retail sectors, in the public sector and in information sector (where union membership density rose 1.9 percentage points).
• Union membership density was stable or grew in a number of Southern states: Arkansas, Florida, Georgia, Louisiana, and Virginia with especially strong growth in Texas.