Working Progress 3: Holt and Winter's Model

Holt and Winters extended Holt’s method to capture seasonality. The Holt-Winters seasonal method comprises the forecast equation and three smoothing equations one for the level ℓtℓt, one for the trend btbt, and one for the seasonal component stst, with corresponding smoothing parameters αα, β∗β∗ and γγ. We use mm to denote the frequency of the seasonality, i.e., the number of seasons in a year. For example, for quarterly data m=4m=4, and for monthly data m=12.a

$m=12$

Reference: https://otexts.com/fpp2/holt-winters.html

Results were not that good and thus the model was discarded as SARIMAX gave better results.