Only about 7 percent of private sector workers are now unionized

In the 1950s, 35% of private-sector workers belonged to unions; only about 7% do today.

The economics point here is pretty simple. You raise the price of something (labor through unionization) and people demand less of it. Sometimes the adjustment takes a long time, but it still occurs.

I recommend that people read the entire piece because John Fund does a great job of discussing the Employee Free Choice Act, where 30 percent of workers (some possibly because of union intimidation) can sign a statement that determines whether the entire company is unionized.