[InclinedPlane]

Unions have very little to do with free markets, and they typically do not actually benefit everyone in labor (they benefit some folks who are already in the union). Because of the way our labor laws work unions, in the instances where they are prevalent, tend to end up being a monopoly on labor for a given industry. This creates distortions in the market just as great as monopolies of capital. Also, unions tend to erode meritocratic systems of compensation and advancement and replace them with systems based on seniority and union membership, which tends to disadvantage the business, customers, and most workers except those few at the top of the seniority ladder.

[pyre]

  > unions tend to erode meritocratic systems of
  > compensation and advancement

If such meritocratic systems exist, the awards are only dependent on the merits of your corporate politicking skills.

[InclinedPlane]

Let's say you are a tech worker in silicon valley. Your wages and the sorts of jobs you have access to are dependent on the sorts of companies in existence, their needs, and your skillset. If you have a highly sought after skillset then you will be courted by multiple companies who will try to woo you with jobs that you find desirable and competitive compensation packages. Let's say instead you are a dock worker in long beach. In that case your compensation and career opportunities are far more dependent on your union membership and seniority.

Certainly playing corporate politics can also have an effect, depending on the company, but that's also true in union shops as well.

[cdcarter]

Very few unions have a mandatory favored nations policy. If you were significantly better at dock workering, such that a company sought you out, they can easily pay you more. That being said, many union labor positions don't have a wild variety of skillsets. They often do need protection.