As our national battle over the Common Core standards escalates this year, remember that new standards and curricula rarely improve schools, says Jay Mathews for the Washington Post. What does work is families becoming more affluent, teachers becoming more proficient and students spending more time and energy on their studies. New lesson plans and textbooks such as those being unleashed by the Common Core in nearly all states have no effect on parental income. Some teachers and students may do better when there are changes in what they study, but so far there is little proof of that. That does not mean, however, that we should dump the new standards…