sunspots

https://mpra.ub.uni-muenchen.de/40271/1/MPRA_paper_40271.pdf

"on the world scale, over the last 44 years (for which the data is available), all 4 maximums of the solar activity overlapped with minimums of the unemployment rate in the G7 countries, followed by its spikes within 2-3 years. From 1965, when consistent recession dating is available for all G7 countries, nearly 3/5 of the recessions started in the 3 years around and after the sunspot maximums. "