Correcting for seasonality!!

[Sherlock.Holmes]

Can someone please explain correctly for seasonality, I'm really confused on whether we should increase or decrease to correct seasonality.

Thanks

[S_R_K]

If the seasonal index is > 1, then the effect of seasonality is to increase the value above what it otherwise would have been. Hence, to correct for seasonality, you need to to decrease the value.

If the seasonal index is < 1, then the effect of seasonality is to decrease the value below what it otherwise would have been. Hence, to correct for seasonality, you need to to increase the value.

In either case, to correct for seasonality, the factor by which you should multiply is given by 1/SI.