I'd be interested in seeing a causative model for this. My guess is that it's purely Hispanic vs. non-Hispanic distinction. The Hispanic kids grow up in mostly

I'd be interested in seeing a causative model for this. My guess is that it's purely Hispanic vs. non-Hispanic distinction. The Hispanic kids grow up in mostly uniformly Hispanic environments, so they have less need to learn English, while latter grow up in more diverse environments. If hardly any neighborhood kids and classmates speak your native language, you need to learn English to communicate with them, while if you're Hispanic, chances are you're growing up in a majority-Hispanic neighborhood and are going to majority-Hispanic school, so you can do mostly fine with only basic English skill. The same thing is true about your parents, so poor English proficiency of kids is not caused by poor English proficiency of parents, but rather both are caused by the same factor.