Any serious conversation about changing the equation needs to start from the perspective of capacity utilization. We certainly need to increase the number of housing units, however, if the utilization rate remains the same or drops, you've really not created any new housing. In southern California we see new projects being built that are $3,600 / month for a 600 sqft 1br/1ba apartment in mediocre neighborhoods or next to freeways. From a bay area perspective, this may seem cheap, but wages are lower here and IPO opportunities are not as rich. Looking at public documents for the REIT that owns one of these aforementioned luxury properties showed a 40% occupancy rate, which wasn't a surprise given the price.
So until municipalities want to really study the overall capacity and exactly how it is being used, changing tax policies will be unlikely to address whatever the real issue happens to be. Our problem is not simply "supply and demand", it's more subtle than that.
If I were still in the multi-family residential marketplace I'd be buying and converting to short-term rentals in cute neighborhoods. It would be the highest and best use of capital deployment under current legal structures.
Wouldn't a SANKEY diagram showing incoming units and utilization of such units be a nice way of seeing the problem and making adjustments? Having such data would be fascinating.