Teacher's Unions - Education's Friend or Foe??

A touchy subject - I know, but. . . Teacher's unions - called "associations" - are a product of the Industrial Age- they were needed to protect workers from seemingly random acts of favoritism or retaliation. The problem is, teachers aren't blue collar workers cranking out products on an assembly line or following an algorithm that is well-known and documented and that can be "six-sigma'd". The are white collar professional tasked with the formidible job of applying science and art to help individuals realize their potential, pursue their passions, and prepare for a bright future. Seniority and educational level have little relevance in this world. I do understand the angst, however. Since education typically only measure and counts "inputs" rather than meaningful outcomes, it is frightening to think about evaluating, paying, promoting, and dismissing teachers based upon outcomes that, honestly, aren't directly measurable in most cases.

You see, teachers are tasked with producing learning, and learning is an emergent property - it must be produced in context and in real time. What I learn in one context doesn't necessarily translate into another without re-learning in that context and real-time experience. This makes determining the quality of a teacher a difficult task - but one we must figure out.

The interesting thing to me is that if I walked into any local high school and stopped 15 random kids and asked them to tell me who the best and worst teachers in the building are, I'd get a pretty consistent list of names and reasons. Same applies to principals, secretaries, etc. So why is it so hard to escape the old experience and education linear progression of pay, seniority and security?

What say you?