Is There Data Adm on Teacher Shortages?

There's active discussions going on in the united states of allowing people without the necessary credentials to start teaching. This has been experimented with around the world, and as you'd expect, it's hugely controversial amongst those who are committed to a more professionalized model of education. The question is however, how much the arcon confounding factors here affect results. And many of the parachuted, in non certified teachers are being used in the toughest class rooms because that's where the problem is largest.