Summary: This post is based on a research note I wrote asking whether low unemployment is sustainable. The answer is a clear no for the US. Low level of unemployment are good predictors of the tail risk event of a recession, a sharp increase in unemployment rates. These dynamics are related to the build up of financial and macroeconomic imbalances. If this pattern is to repeated, and given the current level of unemployment rate, a US recession must be around the corner. For details on the analysis, the research note including additional results is available on my web site: Fatas (2019) . A few months away from the longest US expansion The US economy is a few months short of beating the longest expansion ever, which took place from March 1991 to March 2001. As we approach this milestone, there are increasing concerns about the possibility of a recession in the coming years. Do expansions die of old age? The empirical evidence suggests that this is not the case. There is no clear correla...