Clement Juglar

Clement Juglar, French economist and a contemporary of Jevons (although there appears to be no connection in their work) studied the rise and fall in interest rates and prices in the 1860’s. He found boom and bust waves of 9 to 11 years. Juglar also identified four phases to each wave: prosperity, crisis, liquidation and recession.

The cycle of this period is known as a Juglar cycle.
The following two graphs show the Juglar cycle in the US economy.