That interest rates were on downward trend for centuries has already been observed by Adam Smith in “Wealth of Nations” in 1776. He claimed that governments can

That interest rates were on downward trend for centuries has already been observed by Adam Smith in “Wealth of Nations” in 1776. He claimed that governments can borrow at 2%, and private borrowers of good repute at 2.5%. Considering that inflation at the time was almost 0%, these were basically real rates, and would today correspond to nominal rates of 4-4.5%. Point here is that in England, rates were already very very low in 18th century.