Just in time for Labor Day, Labor Secretary Thomas Perez is resurrecting the old canard that workers do better in unions. His latest blog post uses misleading data to suggest that if workers were unionized, they would receive $200 more per week.

Of course, anyone would want a $200 a week raise. That’s $10,400 a year. But the facts aren’t so simple.

Let’s look at the Bureau of Labor Statistics data itself.

Perez compares median weekly earnings for union members with non-union members. This is misleading because union members are not equally distributed across occupations, industries and regions. Union members are more concentrated in higher-paying government-sector jobs, including teachers and federal employees. Forty percent of union members are public-sector employees. The BLS data that Perez cites do not separate public and private-sector workers.

Read the article “Workers Don’t Do Better in Unions” on marketwatch.com.