(RE)Ranking New Jersey’s Achievement Gap
New Jersey’s current commissioner of education seems to stake much of his arguments for the urgency of implementing reform strategies on the argument that while New Jersey ranks high on average performance, New Jersey ranks 47th in achievement gap between low-income and non-low income children (video here:http://livestre.am/M3YZ). To be fair, this is classic political rhetoric with few or no partisan boundaries.
As I have been discussing on this blog, comparisons of achievement gaps across states between children in families above the arbitrary 185% income level and below that income level are very problematic. In my last post on this topic, I showed that states where there is a larger gap in income between these two groups (the above and below the line groups), there is also a larger gap in achievement. That is, the size of the achievement gap is largely a function of the income distribution in each state.
Let’s take this all one more, last step and ask – If we correct for the differences in income between low and higher income families – how do the achievement gap rankings change? And, let’s do this with an average