Economic decline

The phrase "economic decline" occurs increasingly in Google Books from the early 1970s to the early 1990s. These dates match two decades of low productivity of the US economy.

Usage of the phrase declines from the early 1990s to 2008, the period that contains the high-productivity "new economy" Greenspan talked about. That period that ended with the financial crisis.

Usage of the phrase increases from 2008 to 2015 -- a good match to the years the Fed held interest rates at zero. Things were improving at a snail's pace, give or take.

After 2015, things were improving enough you could see improvement. Trump took credit for that improvement -- and he still does, today. I credit the decline of private-sector debt.