[gmarx]

There are many situations in economics in which the marginal effects are quite large especially WRT setting prices. I haven't read or done an analysis but I would never assume that 5% of a market has a 5% influence only in determining prices

[arebop]

SF City Economist Egan took a more careful look and estimated that SF's housing prices could be changed significantly by adding 100k housing units [https://www.sfexaminer.com/news/leveling-sf-housing-field-co...]. Maybe in some markets, like Venice Italy, you could make housing a lot cheaper by enacting a total ban on tourism. But I remain unconvinced that tourism in general or AirBnB in particular is a major factor in general. We can see from Egan's study that it isn't in San Francisco where tourism is our #2 industry, it's impossible to believe that across the country and around the world travelers are meaningfully preventing locals from finding a place to live. People just don't travel that much!

Also, this trick only works once. After we've eliminated global tourism to add fewer than 5% more houses globally, we cannot do it again next year and forever after to keep prices down while we continue to allocate increasingly more of society's wealth to the fixed supply of housing.