I wondered it there was a break point around 1980. I don't think there was.
I was wrong.
To make a point about the increase in the Finance share of corporate profits over the post WW II period, I took a 13 year moving average of the data. This is what it looks like.
6/16 Update: Underlying quarterly data is in the thin purple line. Long averages are in green, through 1985, and red from 1986 on. Upon rereading, I see how I could have caused some confusion, without this information. I want to be clear, not confusing. Sorry that this post does not meet that standard.
A long average filters out the hash, and reveals the underlying trend. Or, I should say, trends, since there are two, with a sharp break at the beginning of 1986. A trend line on the data through '85 is a near-perfect match to the average line, which barely even wiggles. We see a bit more action in the post-85 segment, but the new trend is still very clear, indeed. The earlier trend line in green is now the lower channel support line.
Well, as I always say, policy matters. Was there anything that changed in the 80's that might have facilitated this shift?
The times of those last three peaks in the quarterly data are Q1-86; Q1- 91; and Q3-01.