Economist Robert Reich says inequality has skyrocketed as unions have weakened. That is no accident and it's why we have to strengthen unions now!
How Dues are Determined
Sometimes dues are set at a flat dollar amount. If your union uses this approach, then you and all your co-workers pay the identical amount in dues, regardless of the fact that your earnings vary by quite a bit. Rather than setting dues at a dollar amount, some unions establish dues as a percentage of salary. When this method is used, everyone in the bargaining unit pays dues based on the same percentage. Your union may use a variation, with the amount of union dues determined by brackets of earnings.
—Adapted from The Union Member's Complete Guide, by Michael Mauer.