At first glance, the key ideas of The Black Swan and The Great Depression Ahead might seem to be direct opposites. The Black Swan suggests that the most important events coming can’t be predicted, and based on that, why bother predicting anything? The Great Depression Ahead, by contrast, says that the most important forces at play in the economy are the easiest to measure and predict because they are cycles that take place over an extended period of time.
Look at it another way, though, and both books are about echoes. They both suggest that you can find meaning in echoes.
The Black Swan says that ordinary events are of no consequence because there is nothing new in them — there are echoes of originating events, or Black Swans. If you look at ordinary actions, they can point you to the original actions that you really want to find out about.
Yet The Great Depression Ahead looks at ordinary activity and ends up pointing in a different direction — looking not to the past, but to resonances. A resonance, in acoustics, is a quality of a physical shape that organizes echoes so that a specific frequency of energy is emphasized. Resonances give musical instruments their musical tones. Elsewhere, in a mechanical design, resonances may be a design flaw that makes a machine rattle in a certain way no matter what work it is doing. If ordinary economic activity consists of echoes, then those echoes form resonances that determine the shape of much of what happens in the economy.
Those resonances are the cycles that form the core of The Great Depression Ahead. The value of measuring resonances is that they remain essentially the same regardless of the source of energy. In a familiar example, you hear the same characteristic sound of an auditorium whether its walls are echoing a Shakespeare play or a string quartet. You can close your eyes and still tell what room you’re in. In the same way, all the unpredictable changes that have taken place in the economy won’t change the resonant cycles in the economy unless the whole structure that supports the resonances has been rebuilt in a different shape. Regardless of the innovations, they tend to form the same echoes.
And so, using the view of The Black Swan, you can ignore the echoes when you are trying to predict the future because the important changes come from the unpredictable Black Swans, while in The Great Depression Ahead, the Black Swans mostly don’t matter because they form the same familiar echoes and resonances, which shape the future direction of economic activity in a way that, because it moves slowly, is somewhat predictable.
In the end, both are correct. It is possible to predict the recurrence of many of the same forces that caused the Great Depression, yet that does not mean we are doomed to experience a repeat of the Great Depression. The story of the economy over the last 81 years is not merely ups and downs, but has more to do with sudden changes, or Black Swans: the eradication of polio, the cellular phone, electronic banking, urban mass transit, and so on. We might be facing the next version of the same 80-year wave that we saw in the Great Depression, but the economy is 10 times the size and has resources — material, informational, and spiritual — that we didn’t have then. Some of the economic measures are bound to echo the Great Depression in the coming decade, but it would be a mistake to imagine that the story of the next decade will be a repeat of the story of the Great Depression.