This might be a bit off the topic but the reason my husband and I decided to get a house was because we have a family. However, although this was in line with the "American Dream" of owning a home, the other major reason we wanted a home was because Apartments had become a bit cost prohibitive. The slight increase we've had in our expenses (garbage disposal, a pittance & water bill, some apts do charge you for your water), are still less than what we would pay for a 3 bedroom in a complex suitable (and I don't mean suitable in a snobbish way, face it there are some places you just DON'T want to live).
So basically, not only did the growing inventory affect housing prices, but it affected apartment prices as well. I'm probably not the only one who basically got "pushed out" of being able to afford an apartment. Plus our rental rates went up considerably every single year. The final push into looking to buy a home was because our rent on a three bedroom, a very BASIC three bedroom (the kitchen was an afterthought and then they shoved a washer & dryer in a tiny closet in the afterthought of a kitchen) went up from $930 per month to $980 per month.
We did look around a bit at other apartments (the one we were in was going to shit anyway) and there wasn't a decent (again, not snobbishly so) apartment for less than $1200 per month. Our house payment is less than $1000 a month AND we have 4 BR/3 BA as well as a sizeable yard.
I'm not sure where I'm going with this train of thought but its something along the lines of a snake eating its own tail. At least, that's the image that keeps popping into my head.
Edit:
Ok now I figured out where my brain was taking me. Isn't it possible that propping up housing prices is going to also erroneously inflate apartment rents? I really think it has a direct affect. Would "mark to market" in anyway have this affect as well? Just thinking out loud now.