Skepticism About Study Linking Trump Support To Racism

Or Dear God More Suspicious Statistical Analysis

So I see people posting this vox article suggesting Trump, but not Clinton, supporters are racist and I want to advise caution and urge people to actually read the original study.

Vox’s takeaway is,

All it takes to reduce support for housing assistance among Donald Trump supporters is exposure to an image of a black man.

Which they back up with the following description:

In a randomized survey experiment, the trio of researchers exposed respondents to images of either a white or black man. They found that when exposed to the image of a black man, white Trump supporters were less likely to back a federal mortgage aid program. Favorability toward Trump was a key measure for how strong this effect was.

If you look at the actual study its chock full of warning signs. They explicitly did not find any statistically significant difference between those Trump voters given the prompts showing black or white aid recipients degree of support for the program or degree of anger they felt or blame they assigned towards those recipients. Given that this is the natural reading of Vox’s initial description its already disappointing (Vox does elaborate to some extent but not in a meaningfully informative way).

What the authors of the study did is asked for a degree of Trump support (along with many other questions such as liberal/conservative identification, vote preference, racial resentment giving researchers a worryingly large range of potentially analysises they could have conducted). Then they regressed the conditional effect of the black/white prompt on the level of blame, support and anger against degree of Trump support controlling for a whole bunch of other crap (though they do claim ‘similar’ results without controls) and are using some dubious claims about this regression to justify their claims. This should already raise red flags about research degree of freedom especially given the pretty unimpressive R^2 values.

But what should really cause one to be skeptical is that the regression of Hillary support with conditional effect of black/white prompt shows a similar upward slope (visually the slope appears on slightly less for Hillary support than it did for Trump) though at the extreme high end of Hillary support the 95% confidence interval just barely includes 0 while for Trump it just barely excludes it. Remember, as Andrew Gelman would remind us the difference between significant and non-significant results isn’t significant and indeed the study didn’t find a significant difference between how Hillary and Trump support interacted with the prompt in terms of degree of support for the program. In other words if we take the study at face value it suggests at only a slightly lower confidence level that increasing support for Hillary makes one more racist.

So what should we make of this strange seeming result? Is it really the case that Hillary support also makes one more racist but just couldn’t be captured by this survey? No, I think there is a more plausible explanation: the primary effect this study is really capturing is how willing one is to pick larger numbers to describe one’s feelings. Yes, there is a real effect of showing a black person rather than a white person on support for the program (though showing up as not significant on its own in this study) but if you are more willing to pick large numbers on the survey this effect looks larger for you and thus correlates with degree of support for both Hillary and Trump.

To put this another way imagine there are two kinds of people who answer the survey. Emoters and non-emoters. Non-emoters keep all their answers away from the extremes and so the effect of the black-white prompt on them is numerically pretty small and they avoid expressing strong support for either candidate (support is only a positive variable) while Emoters will show both a large effect of the black-white prompt (because changes in their opinion result in larger numerical differences) and a greater likelihood of being a strong Trump or Hillary supporter.

This seems to me to be a far more plausible explanation than thinking that increasing Hillary support correlates with increasing racism and I’m sure there are any number of other plausible alternative interpretations like this. Yes, the study did seem to suggest some difference between Trump and Hillary voters on the slopes of the blame and anger regressions (but not support for the program) but this may reflect nothing more pernicious than the unsurprising fact that conservative voters are more willing to express high levels of blame and anger toward recipients of government aid.

However, even if you don’t accept my alternative interpretation the whole thing is sketchy as hell. Not only do the researchers have far too many degrees of freedom (both in terms of the choice of regression to run but also in criteria for inclusion of subjects in the study) for my comfort but the data itself was gathered via a super lossy survey process creating the opportunity for all kinds of bias to enter into the process not to mention. Moreover, the fact that all the results are about regressions is already pretty worrisome as it is often far too easy to make strong seeming statistical claims about regressions, a worry which is amplified by the fact that they don’t actually plot the data. I suspect that there is far more wrong with this analysis than I’m covering here so I’m hoping someone with more serious statistical chops than I have such as Andrew Gelman will analyze these claims.

But even if we take the study’s claims at face value the most you could infer (and technically not even this) is that there are some more people who are racist among strong Trump supporters than among those who have low support for Trump which is a claim so unimpressive it certainly doesn’t deserve a Vox article much less support the description given. Indeed, I think it boarders on journalistically unethical to show the graphs showing the correlation between increasing support for Trump and prompt effect but not the ones showing similar effects for support of Hillary. However, I’m willing to believe this is the result of the general low standards for science literacy in journalism and the unfortunate impression that statistical significance is some magical threshold.

Study: Trump fans are much angrier about housing assistance when they see an image of a black man

All it takes to reduce support for housing assistance among Trump supporters is exposure to an image of a black man. That’s the takeaway from a new study by researchers Matthew Luttig, Christopher Federico, and Howard Lavine, set to be published in Research & Politics.