Measuring Socioeconomic Status
6. How SES Should Be Measured
Recall that there is no consensus definition of SES and in my opinion probably never will be. Therefore, with a variety of SES measures at least theoretically available to the researcher, the natural question is which one should be used? Which is best? Regrettably, I must write that it depends…
On one level, there are pragmatic concerns. In short, one should collect as much socioeconomic data as reasonably possible; the more the better. But given real world constraints, the amount of SES information that can be collected is often limited to conventional measures of educational attainment or annual household income. If one is working with existing data, there are obviously limits to the availability of measures. If the Duncan SEI exists in the data being analyzed then using it seems prudent. If you are left with nothing but a coarse measure of educational attainment, then use it. Relatedly, it may be prudent to measure SES as previous researchers did, even if you disagree with the approach taken, since this will enhance comparability (or replication) of prior work. For better or worse, comparing estimated relationships between SES and health in, say, two source population requires the same measure of SES be used.
However, I hope that my “it depends” answer gains some intellectual traction when viewed at a deeper level. The key idea is that one should collect data appropriate for answering their particular research question. In other words, since there is no agreed-upon measure of SES, researchers should select the one that best informs their research question.