My personal observations — having worked in both high-performing and low-performing schools — are that the lower-performing schools actually have better, more dedicated teachers. API scores are a better indication of the neighborhood demographics than they are of actual school/teacher quality.
It is a fact, though not “PC,” that higher-IQ parents tend to have children with similar IQs. Higher IQs are usually correlated with greater incomes (BTW, you will also find many criminals and mentally/socially disturbed people who have exceedingly high IQs, so it’s not always a good thing).
Most parents want their children to live in safe, clean, comfortable neighborhoods with people who share the same values. Those with higher IQs and incomes will likely choose the best locations, and you’ll see that the high-scoring schools just happen to be in neighborhoods where a disproportionate number of people have higher IQs, college degrees, and incomes.
IOW, it’s not the schools, but the neighborhoods that people are paying a premium for. The API scores are a good indication that the surrounding areas will be safe, clean and full of people who value education, and don’t do drugs, don’t engage in violent acts, etc.
