"The question is: What explains this? We don’t know with any precision. In our paper, we reviewed literature on racial bias and pointed to its potential as an explanation, writing: “Our findings are generally consistent with the widespread presence of anti-Black bias.” We left it for future work to explore some of the relevant mechanisms that link bias to valuations and quantify their importance."

So the thought is that it MIGHT be bias (a bit presumptuous then to title the study "Biased appraisals..."). And we are waiting on future studies to actually provide the causal link.

But even if every bit of the 23% delta is caused by racial bias, we need to consider the trend. As far as I can tell every important sociological data point on this matter (employment, wealth, marriage, laws, etc.) has been improving decade after decade. I don't know what numbers this same study, or one equivalent to it, would reveal from say 5 or 7 decades ago, but I assume it would have been substantially worse.

All of which is to say that proposing a narrative that racism is rampant and getting worse does not seem to be supported by the data. To the contrary, it would seem that it is less than it's ever been and continues to decline.

EDIT: To be clear, I am not suggesting you or anyone here is proposing a narrative that racism is rampant and getting worse. But I think it's safe to say that proposal is prevalent in pop culture.

I'm not familiar with a narrative that racism is getting worse. My impression (and I thought this was in line with US liberal thinking) is that we are now beginning to admit that racism didn't go away with the end of slavery, it didn't go away with the end of segregation; it's still here. I'd say things are getting better, because many white people acknowledge racism instead of pretending it doesn't exist.