In democratic societies, elections are determined by the vote of the people. The democratic process in the United States elected President Trump in 2016. Four years later, after all legal votes are counted and verified, the same process may require that he peacefully transfer that power to someone else.


Economic time series exhibit periodically recurrent movements at the daily, weekly, and monthly levels. Also known as seasonality, it has been usually treated as a nuisance to be removed prior to analysis. Often, data is already deseasonalised by data providers since it distracts from medium-term time trends and long-term cycles. Moreover, seasonality disappears when data are aggregated to a yearly basis – it is a phenomenon at work at shorter time frames. It is an…