I like the little detour through "uncritical analysis of rent control in post-WW I New York" which shows that the author is at least ignorant of one topic, and perhaps others.
"What they often found was discriminatory high rents. Rent was exorbitant for black New Yorkers in the 1920s: A study by the New York Urban League in 1927 found that rent for black New Yorkers had doubled since 1919 while increasing only 10 percent for white residents. Black residents had to pay far more than white residents for virtually identical apartments."
New York passed rent control in April 1920, as a result of skyrocketing rents due to a housing shortage caused by WW 1. It had provisions for control for renters with tenure.
Meanwhile, this period saw an enormous influx of black people to specifically Harlem.
Additionally, there was significant inflation beginning on 1920 on the heels of monetary policy used to address the War (resulting, ultimately in the Depression of 1920-21).
So, supply is low, demand is high, including inflationary pressures. The legislatures pass laws to curtail rents on existing tenants, leaving only new tenants to suffer the burdens of rent increases.
So, while it may be easy to say "black people paid higher rent, must be discrimination" - and some of that might be true - it is probably more fair to say that a poorly-considered rent-control scheme coupled with the results of monetary policy during WW1 and an accident of demographic change, resulted in a coincidence.
New renters paid significantly more rent that tenured renters. New renters happened to be black, because that demographic was shifting.
It is notable that the principal region - Harlem - had been a traditionally Jewish area, and whatever discrimination looks like today, it's not like Jewish New Yorkers were getting a free pass on discrimination in the 1920s. It is much more likely that delta in demographics was largely coincidental.