I'm concerned about the effect this could have on family housing in San Francisco. If a family already owns a house and uses airbnb to rent out a downstairs be

I'm concerned about the effect this could have on family housing in San Francisco. If a family already owns a house and uses airbnb to rent out a downstairs bedroom now and then, sure, I could see that helping. But if a family is in a bidding war with someone without kids, the anticipated income from an airbnb rental could enable the bidder without a child who needs an extra room (to say nothing of the very high costs associated with raising a kid in SD) to go much higher. This would have the effect of making it harder for families to purchase what is currently zoned as single family housing. Now, this is just a concern. It may not currently be happening, and it may be unlikely to happen in the future. According to this post, Ken Rosen, an economist at UC Berkeley, conducted a detailed study for airbnb and states that "...not only is there no evidence to suggest that short-term rentals are making homes less affordable, our research and analysis indicate that home sharing has the potential to make urban housing more affordable for more families." I was unable to find a link to this study on the blog post... is this it? http://urbanland.uli.org/news/short-term-rentals-and-the-housing-market/ http://urbanland.uli.org/news/short-term-rentals-and-the-hou... The only reference I get to a "family" here is "...the amount of income from a rental alone is not generally sufficient to live on, but it can go a long way in providing supplemental income for a family." Sure, but is a family as able to access this supplemental income as someone without kids, and more free bedrooms? And what about the "bidding war" scenario, above? Even if it is not a big factor now, it could become a big factor once the expectation of rental income becomes the norm. The urban land article references this study: http://www.rosenconsulting.com/products/rentalreport.html http://www.rosenconsulting.com/products/rentalreport.html The roseconsulting link makes no reference to families. I recommend people who are interesting read it. The summary is that other factors have led to the rise in housing costs, including restrictive zoning laws and an employment boom, and that airbnb (and related) rentals are too small a part of the rental market to have much of an effect. Does this mean they could have a large effect if it become more widespread?