[ch4s3]

There aren't that many. NYC housing data is sliced, diced, and studied by so many agencies, non-profits, think tanks, and so on that someone would notice. There's a marginal number of units that appear to largely unoccupied. Corporate and LLC ownership shows up in tax data and the totals are a drop in the bucket of the nearly 4 million units.

[chiefalchemist]

Yes, but you only need one unit per building to be over-bid and that then drives up the prices of other units in that building? It might not be an occupancy issue per se, but it doesn't help the overall residential market.

[ch4s3]

Housing exists in price bands more or less, so the thing you’re measuring has to be large enough to have an effect on the band. There’s a lot of research on NYC housing issues and no one has ever identified corporate housing as a contributing factor, so there’s a very high burden of proof on your claim.