How did they get to this conclusion? For every school district in the US, the researchers used the Stanford Educational Data Archive to figure out 1) the median household income within each school district and 2) the grade level at which the students in each school district perform (based on federal test performance).
This piece also provides multiple examples for use within the statistics classroom. Highly sensitive examples, but good examples none the less.
-Most obviously, this data provides an easy-to-follow example of linear relationships and correlations. The SES:school performance relationship is fairly intuitive and easy to follow (see below)
|From the New York Times: Positive linear relationship between parental SES and performance on standardized tests|
-The data provides a good example for explaining between group and within group differences. As discussed, between school districts, high SES students outperform low SES. However, within school districts, white students out perform black and Hispanic students (see below: Here, the data is divided by school district as well as white, Hispanic, and black students within each district).
|From the New York Times: SES x test performance x race|
So, there is a lot to unpack here. A lot of sensitive stuff to unpack. However...it is all illustrated with interactive scatter plots that beautifully illustrate correlation and linear relationships.
I think caution should be used with this example. You can also delve into issues of race. The data demonstrates, time and time again, that if you break up data by ethnicity, regardless of SES, white students perform better than Latino and African American students. There are many historical/SES issues related to underperformance among African-American and Latino students. If you are going to share the data related to these issues, I think that it is worth the time to address these so that racial stereotypes aren't used to explain this data (the authors of the NYTs piece do a good job of doing so).