The reality is that most non-black homebuyers try to avoid predominantly black neighborhoods. This alone already brings down the property value. If you live in a state that has one city with a large black community, that typically has a lot of problems, most likely non-blacks already view blacks unfavorably.
Lowering the price may make it more desirable to non-black homebuyers OR make it more accessible to black homebuyers, who may not have as much purchasing power.
To be honest, the real estate market is just responding to the buyers out there.
And this lady's experiment didn't really prove anything since she used two different appraisers. The second one may have given her the same value as they did her husband.
This wasn't exactly a good experiment.