The Greatest Age of the Inducement to Investment ?

FRED has some data from the Bank of England, from their "Three Centuries of Macroeconomic Data" project. I happened to look at one graph and, well, first things first:

Bank of England, Hodrick-Prescott (HP) Filtered Log of Real Gross Domestic Product at Factor Cost in the United Kingdom [HPGDPUKA], retrieved from FRED, Federal Reserve Bank of St. Louis; https://fred.stlouisfed.org/series/HPGDPUKA, April 27, 2019.

Graph #1

What's that, the "Great Moderation" to the right of the mid-graph hyperactivity? Can't be.

There are alternating periods of high and low amplitude. I see three quiet periods:

• A mid-length one around 1500
• A very long one after 1700, and
• A very brief one after 1950.

To see a version of the graph big enough to read the dates, click the graph.

The brief quiet period, after 1950, that's actually the 1960s. Ain't that odd?

I should say, I don't know what the hell this graph is. I know, it's "Percentage Difference from Trend". So the black line, the zero line, is the "trend" after the trend has been subtracted from the data. And the trend was probably figured using the Hodrick-Prescott calculation (which they call a "filter"). And they probably started with "logged" values for Real GDP.

Doesn't matter what the graph is. I'm just looking at it. And I was wondering, what can that long quiet period be, if not the Great Moderation? Here's my guess: It's the 150 years of "the greatest age of the inducement to investment" as described by John Maynard Keynes:

Graph #2

Click the damn graph.