Guest Eliza-
Bright, well-off, socially secure kids will learn---they always do. It's the poor, the immigrants and those from disheveled social environments that will fall by the wayside. And tenure, while often abused, is the only think that keeps the system from firing higher-paid teaches whenever there's a budget crunch. Good teachers are obviously a wonderful thing---making jobs insecure isn't the way to attract good minds to the profession.