at hot issues out west, proposition f is a measure on the san francisco ballot that would limit short-term rentals to 75 days and require companies like air b and b to remove listings that violate the limit. joining me now, msnbc business correspondent olivia sterns. what's at stake today in san francisco? >> this is a really interesting one. you can sort of think of it as the first public referendum on the sharing economy on a big tax start-up. today residents in san francisco are being asked to vote on proposition f. it is a proposal to put curbs on air b and b in the city to limit the number of nights that you can put your property on air b and b to just 75. critics in san francisco say that it is exacerbating the housing crisis by turning apartments into hotels instead of having landlords actually lease their apartments out to longer-term rentals. supporters, many of whom include landlords themselves, say actually it is great that i can make this extra money through