So specifically, if you hold constant your education, you stick in percentage of college graduates in your metro area, you will find that has a significant positive effect on your wages without changing your education at all.
具体一些，如果你将你的教育保持不变 把当地的本科生比例加进去 你会发现它对你的工资有明显的改善 而完全不需要改变你的受教育程度