Features: Parsimonious model with differencing handling both trend and seasonality
Model Selection Tips
Use ACF/PACF plots to identify p and q
Apply differencing (d,D) until series is stationary
Set m to match your data frequency (12 for monthly)
Compare models using AIC, AICc, or BIC criteria
Educational Insight: The optimal model SARIMA(1,1,0)(0,1,0)₁₂ uses:
• d=1 to remove the trend through first differencing
• D=1 to remove seasonal pattern through seasonal differencing
• p=1 for short-term AR(1) autocorrelation
• P=0, Q=0 meaning seasonal differencing alone handles seasonality without additional AR/MA terms
• This is a parsimonious model that captures both trend and seasonality efficiently