When I lived in silicon valley, the local paper would publish the results of student tests in all the public schools. There was a perfect correlation between lower scores and the number of non-native english speakers. No surprise, right? So a big part of the "problem schools" would seem to be immigrants. How do you measure that cost?

I also noticed that a lot of pro-immigrant people lived in expensive neighborhoods with very few illegal immigrants in thier children's schools. So I think everyone who wants unlimited immigration should move to central San Jose, where there are ton's of illegal immigrants.

I did a "ride a long" in a San Jose police car once. There was a map of the patrol zones. They ration the cars so that each one will patrol an area with an equal amount of crime. The areas of with lots of illegal immigrants were tiny. Do the immigrants cause the crime, or do they live there because the rent is cheap?
So hard to figure out! But there are a lot of latino street gangs in these areas, and I don't think the gangs meet to play chess. Other areas have asian street gangs. A latino who grew up in these areas told me that asian gangs are much worse to be around. He said that he often saw his childhood friends in the police beat section of the paper.