FEDERAL FUND RATE AND GEOMAGNETIC INDEX Ap CYCLES (1955–2024)

The paper uses a methodological approach based on W. S. Jevons and A. L. Chizhevsky. The years of solar cycles were numbered according to the order established in solar astrophysics, grouped and compared with the arithmetic mean values of the effective US federal funds rates and the geomagnetic index Ap. The Fed rate is minimal either in the year of the geomagnetic index Ap extremum (this is the first year of the solar cycle) or in the year following it (these are the seventh and twelfth years of the solar cycle) as a reaction to the Ap index extremum. The forecast value of the effective federal funds rate for 2025 is 3.92%, and for 2026 it is 2.81%.