Economist Allison Schrager points out a little-noticed shift in the workforce that explains part of the membership problem Big Labor is facing: Union members are now experiencing declining job security.
This is notable because job security is a key benefit to joining a union in the first place. Unions are supposed to pressure companies to preserve positions, even in hard times. But even union-dominated industries have seen mass layoffs in recent decades.
Also, many of the other benefits that unions provide, like pensions, are only available to people who remain at their jobs for set periods. Without the assurance that they will be at a particular job for a long time, the other benefits unions provide to workers are less of enticement to become a member.