Non-occupying owners are a factor in supply and demand; banning them (or even just increasing costs on them, e.g., via taxes on long-term vacant units) reduces the number of prospective non-occupying owners buying and causes existing ones to sell. Similar factors applies to owners with residences used exclusively as short-term rentals rather than residences, which I would expect are usually more of an issue than units held vacant by non-occupying owners.
> Given how the overwhelming majority of home purchases are still done by owner occupiers
The share purchased by investors has gone up much higher than usual to 24% of single family homes nationally last year, with Georgia leading the nation at 33%: https://www.pewtrusts.org/en/research-and-analysis/blogs/sta...
The problem with this analysis is that it ignores that homes owned by non-occupying owners (ie. landlord) are still occupied by somebody, and is therefore suppressing demand for buying houses. Or put another way, if you got a landlord to sell a home, there would be one more home on the market, but at the same time whoever was previously renting that home will get kicked out and will also need a home, so the net effect on supply/demand is zero.
The only way to bring down housing prices is to out-build the demand -- which no constructor will do voluntarily, because it's a guaranteed loss proposition. Personally, my only hope is that remote work will even out prices between low-value and high-value areas -- but I'm aware that proximity to the job is not the only factor determining the value of an area.
But why are home prices going up? Is it because non occupying buyers are bidding with each other to drive up prices beyond what is rational? If so, banning those buyers might indeed bring prices down to a saner level. However, if prices are high as a result of supply and demand (ie. more people want to live in desirable places and we can't build more homes to accommodate), then banning non occupying buyers won't do much. Given how the overwhelming majority of home purchases are still done by owner occupiers, I'm very skeptical that it's the former, and it's much more likely that it's the latter.