Is the U.S. heading toward social instability after 2020?

I recently heard about the economist Peter Turchin. He claims that there are fairly predictable economic cycles and that we are in the middle of one right now that is heading toward a crisis in a few years. He wrote a book in 2016, The Ages of Discord where he applies his theory to world history. Unfortunately, none of my local libraries have a copy. Turchin claims that he has turned history into a science, what he calls cliodynamics. Here is a link to a brief description.

Is Turchin on to something or is he just blowing smoke? If he is so good, how come I never heard of him before?