Data is over the entire US and are median prices. I would agree that averages would skew the data in favor of one to the other. I always prefer medians over averages. Also, the enormity of the data (the entire US) should balance it well and avoid data skewing.
I don't know, but I would argue that the growth of urban environments vs rural would suggest that the median home today is smaller than the median home in 1970. I agree that the average suburban separated home size grew as people added game rooms, spare rooms, and second living rooms. However, I'd bet the percent of homes being condos and townhouses has grown even more so.
Trust me, I know that there are extremes in the US. Here in the San Fernando Valley, you cannot purchase ANY stand-alone house under $600k unless it's a former crack house without a roof, feces on the walls, and not a single working utility or fixture. $600k will get you a livable 2 bed / 1 bath 900sqft house with a handful of homeless squatters living in 1970s RVs on your curb and tents on the corner. Raising a child here without witnessing Chester the Molester digging through your trash, exposing himself, and fondling it in front of your kid is not a reality.
Think about that. Can a median household income of $56,000 afford the mortgage and taxes on a $600k house?
$56k minus about 35% in taxes / 12 = $3000/month
If they could miraculously come up with 20% down ($120k!), then a 4% mortgage would be $2200/month. Toss another ~$1000 in property taxes a month. $3200. They haven't even eaten or purchased toilet paper to wipe their ass yet.
