we are talking about homeowners who own a 2nd home and in many cases, have bought it expecting to rent it out at least part of the time. they went into that purchase with the mindset of sharing with strangers. i would be very interested in using airbnb if i owned a vacation home.
In general, the people who have 2nd vacation homes buy single family houses or condominium apartments. They don't rent, because that doesn't get them ownership of anything. The 2nd home is generally a more speculative investment than anything else.
So no, they're not really pushing up the costs of rental apartments, because they're not in that market segment at all.
I have no idea if AirBnB does that to apartment rents but I do know that some formerly sleepy coastal towns became too expensive (in recent decades) for locals to buy a house due to second homes being bought there by wealthy non-residents. I have no idea how to fix such a problem but I know it is real.
I am my sister in-law both do this. It's a great way to purchase a vacation home and off-set the cost. Just make sure you financially plan for the worst and hope for the best :)
