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Models for seasonal adjustment of TSI data inputs

Wednesday, July 26, 2017
ModeModel(1)Trading days(2) and holidays(3)Outliers(4)ARIMA
Rail PassengerANo TD; Easter[7], Thanksgiving_7No significant outliers(0,1,1)(0,1,1)
Rail Freight    
CarloadsANo TD; Leap yearLS DEC2008(0,1,1)(0,1,1)
IntermodalsMNo TD; Leap year; Easter[7], Memorial Day, Thanksgiving_8, ChristmasAO OCT2002; LS DEC2008(0,1,1)(0,1,1)
TruckingATD; No holidaysLS MAR2000(2,1,1)(0,1,1)
WaterborneANo TD; No holidays (0,1,2)(0,1,1)
TransitATD; No holidaysAO MAY2007(0,1,1)(0,1,1)
FreightMTD; Easter[2], Memorial Day, Thanksgiving_8AO SEP2001; TC OCT2002; LS NOV2008(0,1,2)(0,1,1)
PassengerANo TD; Easter, Thanksgiving_8AO SEP2001; LS OCT2001(0,1,1)(0,1,1)
Natural gasMNo TD; Leap year; No holidays (0,1,2)(0,1,1)
PetroleumANo TD; Leap year; No holidaysAO SEP2008(0,1,2)(0,1,1)


(1) M = Multiplicative; A = Additive

(2) TD = Trading Days

(3) Moving Holidays/Calendar Effects = Easter, Memorial Day, Labor Day, Thanksgiving, and Christmas.

Easter[n] = number of days n before Easter

Easter = Thursday before to Tuesday after (6 days).

Memorial Day = Friday before to the Tuesday after (5 days).

Labor Day = Friday before to Tuesday after (5 days).

Thanksgiving_7 = Tuesday before to Sunday after (7 days)

Thanksgiving_8 = Tuesday before to Monday after (8 days).


If Christmas falls on a Monday = Friday before through Tuesday after (12 days).

If Christmas falls on a Friday = Wednesday through Sunday after (12 days).

If Christmas falls on a Saturday = Wednesday through Sunday after (12 days).

If Christmas falls on a Sunday = Thursday through Monday after (12 days).

(4) LS = Level Shift; AO = Automatic Outlier; TC = Temporary Change