My claim is that, during the Harlem Renaissance, geographic change promotes opportunity, because if you live in a bad place then you should leave.
One piece of evidence is "Between 1889 and 1932, over 3,700 people were lynched in the United States, more than 85 percent of them in the South. The lack of protection from mob violence was one of the reasons that pushed southerners to migrate north."
This reminds me of today's riots and protests between black and white people, such as the KKK marching through the street and Colin Kaepernick kneeling as a protest because of unarmed black people getting shot by police.
These are similar because they both involve extreme racism / protesting against racism, and if you live somewhere where people treat you like that, you should go so you don't get hurt.