Eviews5 / EViews5 / Example Files / x12 / example11

3 February 1998

Example 11. This example shows two things:
(1) Forecast extension can reduce seasonal adjustment revisions.
(2) Initial trend estimates can undergo revisions that
are reduced rather little by forecast extension, but
revisions to the trend are small by Lag 3.

Forecast extensions with leads 0, 12, and 42 are considered for
the series of South Total Housing Starts. This example is discussed
in Section 3.2 of the article "New Features and Capabilities of the
X-12-ARIMA Seasonal Adjustment Program" that will appeared in
the Journal of Business and Economic Statistics (1998, 16:127-177).



Example 11: soths.mta

Metafile for running the three spec files with differing amounts of forecast
extenion to produce revison histories for South Total Housing Starts.

sothsn0
sothsn12
sothsn42



# Example 11: sothsn0.spc

# For producing seasonal adjustment and trend revision histories for
# South Total Housing Starts for adjustment without forecast extension.

series{
title='SOUTH Total Housing Starts (maxlead=0)'
name='SOTOT'
period=12
file='start64.dat'
format='1R'
span=(1984.1, )
}
transform{function=log}
regression{
variables=(td ao1990.1)
}
arima{model=(0 1 1)(0 1 1)}
estimate{ }
forecast{maxlead=0}
check{print=all}
x11{ }
history{
estimates=(sadj trend)
trendlags=(1 3)
print=all
savelog=(asa atr)
start=1994.1
}