Flutterby™! : Rent Control

I remain super skeptical about rent control's impacts on a community and the political scene that it engenders, but I need to dig a bit into the source material behind this: USC joins growing collection of research that moderate rent regulation in region will alleviate housing crisis . It contains sketchy things like:

However, much of the evidence provided has been either skewed or ignoring social issues like stability within neighborhoods. For example, multiple studies in New Jersey, the most rent-regulated state in the country, have shown that rent control has had little impact on rent levels and availability, contrary to common economic research. But this was because, according to Pastor and his crew, researchers accounted for income levels, the racial makeup of neighborhoods and other related factors.

Like, what does that mean? If "rent levels" means "occupancy", then, yeah, a region with low vacancy rates will have low vacancy rates after rent control too, because nothing's been done to impact supply.

And "...accounted for income levels, the racial makeup of neighborhoods..." means somehow they accounted for gentrification as some sort of externality? The article makes little sense on this matter, but is being passed around by Prop 10 proponents so I'd like to understand it better.