A gradual rise (in the 1990s)

Last in a series

Two notes on Graph #4 from yesterday (here renumbered):

Graph #1: Monetary Interest Paid by Domestic Business, relative to Total Labor Cost

1. The latter half of the graph shows three highs, but these seem to be of three different types:
 a. A sustained high (in the 1980s)
 b. A gradual rise (in the 1990s), and
 c. A sharp rise to peak.

The middle one, b, corresponds to the good years, when productivity was up and the Federal budget got balanced: the "macroeconomic miracle" years. Goldilocks.

2. I wonder if there is some relation between these peaks and Ed Lambert's "effective demand".