I need to test the effect of some predictors over the oil price. I'm fitting ARIMA models to my data.
Could you help me determine whether using a seasonal or a non-seasonal ARIMA model? Is oil price known to be seasonal?
Generally speaking, if I'm not sure about seasonality in my data, what is the best way to test it? Is there a specific test I can use? Or do I just put a variable that indicates the month in a regression model and see whether it is significant predictor?
I found some answers here: What method can be used to detect seasonality in data? But still I'm wondering if there's a specific statistical test I can use.