The problem with the analogy is that the quality of the output of the line is not just the workers (i.e. teachers), it's the quality of the materials going in (

The problem with the analogy is that the quality of the output of the line is not just the workers (i.e. teachers), it's the quality of the materials going in (i.e. students). Good neighbourhoods with low crime and stable, happy family's produce decent students and decent schools. Not just a money or 'quality of teacher' thing. No doubt some teachers are a little better than others, I personally believe that it's not that important. Keeping families employed, stable, keeping gangs at bay, having good role models, low crime, low violence/stress for kids ... these are the big problems.