Textbook Economics, The Decline of Unions
From George Will's most recent column: "Recently, the UAW has been retreating, crippled by economic forces beyond its control — and by its past successes in winning benefits that companies can no longer afford as they compete with foreign manufacturers in America who do not have unionized workers and the legacy costs of union retirees."
In other words, it priced its members right out of the competitive, globalized labor market. It's Econ 101:
From the Gwartney textbook: "For a time, unionized workers enjoy higher wages. In the long run, however, investment will move away from areas of low profitability (e.g. Delphi, Ford, GM). To the extent that the profits of unionized firms are lower (MP: Delphi, GM, Ford), investment expenditures will flow into the nonunion sector (MP: Toyota, Honda, Nissan) and away from unionized firms. As a result, the growth of both productivity and employment will tend to lag in the unionzed sector. The larger the wage premium of unionized firms, the greater the incentive to shift production toward nonunion operations. Empirical evidence shows that industries with the largest union wage premiums were precisely the industries with the largest declines in the employment of unionized workers."
Classic textbook economics in operation: The UAW has seen its membership decline by almost one million members in the last 20 years, and is lower today than at any time since 1942!