The trendline made a big jump in the late 1940s; most economists attribute this to the postwar boom and the rise of the subdivision. There was another increase in the mid-late 1970s as a result of the changes in the tax laws.
As for why break it down to the 50-year cycle, one look at the charts should be sufficient to see that there was one trendline prior to WWII and a separate and much higher trendline starting in 1950. You could say the baby boom really did trigger that different trendline. Bear in mind, prior to this suburbia as such didn’t exist.
Excluding this last spike the 50-year trendline is reasonable consistent; adding in the pre-WWII trendline only confuses things.
Now if one of the bulls can argue what seismic change in our society – comparable to the effects of the baby boom – has basically tripled the rent/price ratios from 1997-2006 then I’m all ears. Absent fundamental indicators to the contrary, and as supported by the recent pricing trends that support the return-to-trendline direction in pricing – I’m of the personal opinion that our pricing structure is going to go all the way and will probably overcorrect some before it stabilizes.
