Union Theory

This will be a short post, as I am not an economist and haven't done any research on the post-topic.  Also, my jargon will be off because I haven't taken econ in years.

Here it is.
Thesis:  Adding constraints or invalidating economic assumptions creates market distortions.

No suprise there, right?

Sub-Thesis:  Labor unions are an externality caused by the invalidation of the homo economicus assumption of perfect mobility.

Explanation:  When I learned about labor markets in Econ 101, I learned that labor is a commodity (more or less) with its supply and demand curves, et cetera.  One of the things that had to be accounted for in assessing prices and elasticity and so forth was the degree of mobility of the labor in question.  Now, it seems that unions were created because workers weren't getting paid commensurate with their working conditions and labor.  The only reason this could have happened is that there were no other acceptable jobs around, and that the workers couldn't move to the jobs they wanted.

Whether those jobs actually existed is irrelevant to this point.

Now, as the workers couldn't move to a better job, there was a market distortion that benefited the employers, namely a lack of competition for labor.  The employers essentially had a captive labor pool and could pay less than competitive-market prices.  So, as the unions formed, they essentially functioned as a substitute for the perfect mobility that the workers lacked.  They acted as an indirect competitor with the original employer.  This moved the overall supply/demand curve intersection to a point closer to that of optimal efficiency.

This suggests that there is an economically optimal amount of union involvement in a given labor pool or situation.  That amount would be just enough to balance the degree of invalidation in the labor-supply-assumption, or perfect mobility, whatever you want to call it.  Further, if there's an optimal amount of union involvement, that means that there are sub-optimal levels-- too high, and too low--and those levels can be determined and compared against reality.

This is a fun academic exercise.  I think it describes why unions formed and a bit of their history.  For predictive theory, it seems that unions would thrive in environments where the facilities are fixed and labor pools are specialized (hence, they have imperfect mobility) and be unable to keep a foothold where labor is fungible and facilities are widely distributed (or where mobility is greater).  Does this accurately describe reality?

It does not describe union pension plans, however-- I think that will take a more deliberate thought-experiment to explain.