Does ATAR measure more than SES?

One reason ATAR is criticised is that it tends to reproduce socioeconomic status.

One of ATAR’s critics complains that it is

“…more likely to measure the relative wealth of schools, more than a student’s abilities. In fact, using a students’ postcode might work just as well.”

Similarly, another critic says that “ATAR scores align more closely to postcode than they do to human potential…”.

While ATAR is not this deterministic – there are a range of abilities in every part of the SES spectrum – it’s true that ATAR correlates with family background, student home location and school attended (the scale of school effects after controlling for SES  is contested).

But that the ATAR achieved is influenced by a student’s social background does not mean it isn’t measuring something real about likely academic performance.

As the chart below shows, fail rates increase as ATARs go down across the socioeconomic spectrum. For a given ATAR, there is very little difference by SES.Grattan ATAR_chartdeck

Similarly, attrition after first year is more closely associated with ATAR than SES, as seen in the chart below. attrit_atar_ses

Although differing slightly in some of the detail, this is consistent with my posts earlier this year arguing that SES has most of its effects prior to post-school education, with  university access, performance and outcomes being similar for low SES students as other students: the same results, or small positive or negatives. It is also consistent with our recent Grattan report on dropping out, which found more narrowly, but also with more statistical rigour, that low SES in itself only had a small negative effect on completion rate.