Permanent Income and the Black-White Test Score Gap
研究发现，控制当前家庭收入只能解释黑-白考试成绩差距的一半，而控制永久收入后差距缩小至0.2-0.3个标准差，加入永久收入后三年级未解释差距降至0.15个标准差以下。
Abstract Analysts often examine the black-white test score gap conditional on current family income. We describe a method for identifying the gap conditional on the family's permanent income. Current income explains only about half as much of the black-white test gap as does permanent income, and the gap among families with the same permanent income is only 0.2 to 0.3 standard deviations in two commonly used samples. When we add permanent income to the controls used by Fryer and Levitt (2006), the unexplained gap in third grade shrinks below 0.15 SDs, less than half of what is found with their controls.