Lying with Math: Gawker on Airbnb
According to Gawker, and this is the verbatim headline, “Damning Analysis Shows Airbnb’s Impact on San Francisco Housing“, and puts up a scary choropleth showing the Mission as bright red:
There’s something about these maps that makes people lose their minds – especially when the map is constructed incorrectly to show absolute numbers instead of density, a cardinal error. This map is thus extremely misleading and produces a perfectly predictable misinterpretation. The Mission is almost always going to be bright red on maps showing absolute numbers, for obvious reasons – it is quite large, and very dense. The awful map is from the Chron, but the flaw in interpretation and misrepresentation about the significance comes from Gawker’s Natasha Tiku. Gawker says – as though it’s some sort of damning statistic – that there are 681 Airbnb rentals in the Mission. Well…okay, is that a lot? The Mission is defined variously, but the average household size is about 2.4 people, suggesting there are somewhere between 14,000 and 16,000 households in the district. At the high end, that means 4.8% of the households in the Mission are available for rental at some points (not all the time), at the low end 4.2%.
Given that it’s not even clear how the availability of Airbnb affects the price of housing or if it affects housing prices at all, it seems like a real leap to imagine that roughly four and a half percent of households are having any detectable effect on housing prices in the city. The San Francisco rent crisis is a real problem and it’s unhelpful when polemicists use bad math to muddy the waters.