2020 is poised to be a great year for Japan. My main scenario is straightforward: exports get lifted by the re-acceleration of Chinese demand and domestic demand strengthens due to strong business investment, fiscal support and a steadfast rise in the purchasing power of Japanese employees.

However, there will be surprises — scenarios not captured by the quantitative models of the experts or the current consensus "wisdom" of the crowds.

Here are the outlier scenarios that keep me awake at night. Improbable as they may seem, any movement toward their far-out direction will force a true about-face in the current consensus. That's why surprises are so powerful.