Hmmm. I'm not in love with the methodology or the dataset the authors use to reach the conclusion that there are no changes in racial discrimination in hiring in the US over the past 25 years.
Let's [look at the data first](http://www.pnas.org/content/early/2017/09/11/1706255114/F1.expansion.html
). The authors collected 24 studies relating to hiring discrimination and plotted the discrimination quotient over time. The slope of the trend line is relatively flat, leading to the conclusion that racial discrimination in hiring hasn't changed over the past 25 years.
But looking at the data, I have a hard time getting on board with that conclusion. For arbitrary reasons, the study began the analysis in 1989. There are three data points here that are anchoring the trend line. Then there is a >10 year gap before the next study. These studies from the early 2000s all showed higher levels of discrimination. If we remove the 1989 studies, or just begin the analysis at couple of years later, we would reach the opposite conclusion - that racial discrimination in hiring practices has gone down over time!
Also, just sanity testing the data makes me wonder how reliable all of these studies are. If we look at the studies from the 1970s, we'd conclude that racial discrimination in hiring is half of what it is today. That fails plausibility testing in my mind.
Further, looking past the data, the methodology doesn't seem great. Here's how they collected the studies:
> First, we identified all existing studies, published or unpublished, that use a field experimental method and that provide contrasts in hiring-related outcomes between equally qualified candidates from different racial or ethnic groups. Second, we coded key characteristics of the studies into a database for our analysis based on a coding rubric. This produced 24 studies containing 30 estimates of discrimination against African Americans and Latinos since 1989, together representing 54,318 applications submitted for 25,517 positions. Finally, we performed a random-effects meta-regression to identify trends over time.
I am not a fan of including unpublished studies here. Crap in, crap out. I'd want to see some sensitivity analysis on what would happen if certain "low quality" studies were removed from the analysis.
Ultimately, I have a hard time drawing any conclusions about trends in hiring practices and racial discrimination from this paper. The data looks messy, and the methods seem dodgy. This isn't a strike against these authors, in particular. Most meta-analyses suffer from similar problems, and should be read with extra caution.
how can one assume that hiring policies are discriminatory?
I take it this is assumed, yes? or is there evidence that indicates this was discrimination?
Wouldn't these same data sets show anything you really wanted them to?
Such as: no change in potential employability among racial categories since 1989?