This is dumb. Obviously, due to supply and demand, adding new housing, with all other factors held constant, would lead to lower rents. However with gentrification all other factors are not held constant. Gentrification happens when the household income of an area goes up due to migration. In this situation the demand side goes up, which can push up rent, especially if the shift happens by replacing low income housing with higher income housing, which is common. This study appears to try to refute peoples concerns about gentrification, but instead it comes off as unempathetic and misleading to me.