Such changes are all but invisible over the short time scale of modern observations, and, it is argued, they are usually obscured by innumerable gaps in the imperfect fossil record.

It is a curious fact that in bad days we can very vividly recall the good time that is now no more; but that in good days we have only a very cold and imperfect memory of the bad.

Although imperfect, these central bank actions have been helpful in moderating the severity of economic cycles over time.