The current issue of The Economist leads off its United States section with a story on public sector unions that breaks down the issue very well.
For years, public-sector workers have basked in an alternative reality. Nevertheless, as private-sector unions have faded, public-sector ones have thrived. In 2008 37% of government workers were unionised, nearly five times the share in the private sector (see chart), and the same share that was unionised 25 years earlier. Over that period, the share of unionised private-sector jobs collapsed from 17% to 8%. In 2009, for the first time, public workers comprised more than half of America’s union members. Democrats in particular have little incentive to anger workers, who are often their electoral foot-soldiers, and neither party wants to prod them to strike, since they hold monopolies. Those who defy unions do so at their peril. In 2005 Arnold Schwarzenegger, the governor of California, tried to curb the unions’ power. His effort was quickly terminated.
The full article is available here (paid subscription required).
For more on public sector unions, see here.