An explanation for relative stability being not normal (from this HN thread):

After WWII many veterans took advantage of the free education offered by the GI Bill. That gave us a lot of highly educated people (with no student loan debt to worry about!) who then went on to use that education to improve things. Couple this with the recent memory of fascism in Europe and The Civil Rights movement and we had sort of a golden era. We were able to live off the fumes of that era until right around the end of the 20th century. You could say that in a sense things are just returning back to a more normal state of affairs and this seems painful because many of us lived through an era that was unusually good.