Unions in Decline: Some International Comparisons: Union membership and clout has been dropping in the US economy for decades. But it's not just a US phenomenon: a similar drop is happening in many high-income countries. The OECD Employment Outlook 2017 discussed the evidence in "Chapter 4: Collective Bargaining in a Changing World of Work."
Here are a couple of illustrative figures. ...
The OECD chapter provides a more detailed discussion... But several overall patterns seem clear.
1) Labor union power is weaker just about everywhere.
2) The extent of labor union power varies considerably across countries, many of which have roughly similar income levels. This pattern suggests that existence of unions, one way or another, may be less important for economic outcomes than the way in which those unions function. The chapter notes the importance of "peaceful and cooperative industrial relations," which can emerge--or not--from varying patterns of unionization.
3) In the next few decades, the big-picture question for union workers, and indeed for all workers, is how to adjust their workplace skills and tasks so that they remain valued contributors in an economy characterized by new technologies and global ties. Workers need political representation--whether in the form of unions or in some other form--that goes beyond arguing for near-term pay raises, and considers the difficult problem of how to raise the chances for sustained pay raises and secure jobs into the future.