Spectral Analysis Of All Cause Death (part 2)

I utilise an engineering tool to investigate periodicity for all cause death within England & Wales by date of death for the period 1st June 2014 – 31st July 2023

In the first article in this series I waffled on about annual periodicity without actually showing this. With a daily data series we are going to find annual periodicity down at f = 0.00274. For those still wondering how this pithering frequency comes about I shall quickly mention that there are 365 days in the year and the inverse of this number (1 ÷ 365) fetches up at 0.00274. In essence 365 is the wavelength. This is a pretty small number to be plotting on an axis that reaches the giddy Nyquistian heights of f = 0.5, so here are five more periodograms for all cause deaths across England & Wales for the date range 1 June 2014 – 31 July 2023 with the x-axis truncated to f = 0.1: