The legislation being proposed also has a bunch of regulation regarding Spanish holdings buying property, including rent price controls. Depending on how you look at it, forcing foreign groups to set up shop domestically and be restricted by that regulation is the entire point of the tax hike.
Spanish media were reporting recently that some existing rental holdings were starting to dump real estate in response to the rent control, at least in Barcelona.
The bigger problem will be whether the legislation package passes in Parliament, where it needs support from conservative regionalists and then gets implemented at the autonomy level (think states, if you’re American), which is largely controlled by conservatives.
See below, the idea is for rent control to take care of that, which is part of the package. Along with the government supposedly planning to build their own company to compete.
If they were able to manage getting this implemented, which is dubious for political reasons, it probably would work, but it’d take at least a few years and there are many ways the increasingly anarchocapitalist conservative forces around it can disrupt it. We’ll see. As a model for other places… it’s probably a good place to start looking, it just needs a legal framework where you can deploy all of it (rent control, direct government development and rental, fiscal pressure on speculative property purchases). Just one piece alone probably won’t do it.