Hi, I am a civil engineer and beginner in eviews. I am trying to estimate future passenger flow data based on the past statistics. I do automatic ARIMA forecasting in eviews. However, the selected model gives a result in the figure attached. It is very different from the actual data. What am I doing wrong?
Forecasting Ridership Data
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- Non-normality and collinearity are NOT problems!
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- Joined: Wed Sep 17, 2008 2:25 pm
Re: Forecasting Ridership Data
Statistics is never as good as knowing about the subject. Using an ARIMA model just forecasts based on previous values. You need to bring your civil engineering knowledge to bear.
What do you think is wrong with the forecast?
What do you think is wrong with the forecast?
Re: Forecasting Ridership Data
startz wrote:Statistics is never as good as knowing about the subject. Using an ARIMA model just forecasts based on previous values. You need to bring your civil engineering knowledge to bear.
What do you think is wrong with the forecast?
Hi,
Thanks for your response.
I am thinking that the forecast should not be steady without any variations in the data. The forecast I made shows a regular profile just with M shapes but same at any stage of the year, no variations during the whole year. Maybe I should do seasonal ARIMA (SARIMA) but I don't know if eviews can do that.
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- Non-normality and collinearity are NOT problems!
- Posts: 3775
- Joined: Wed Sep 17, 2008 2:25 pm
Re: Forecasting Ridership Data
EViews can do seasonal arima, although I think you have to give a specification rather than use the automatic feature. You can also use dummy variables for seasons.
While I don't know much about traffic, from your graph I have a suspicion that the idea "weekend" and "holiday" might be important.
While I don't know much about traffic, from your graph I have a suspicion that the idea "weekend" and "holiday" might be important.
Re: Forecasting Ridership Data
startz wrote:EViews can do seasonal arima, although I think you have to give a specification rather than use the automatic feature. You can also use dummy variables for seasons.
While I don't know much about traffic, from your graph I have a suspicion that the idea "weekend" and "holiday" might be important.
How can I give this kind of specification?
-
- Non-normality and collinearity are NOT problems!
- Posts: 3775
- Joined: Wed Sep 17, 2008 2:25 pm
Re: Forecasting Ridership Data
@weekday gives the day of the week. You probably want to use the ls command to specify an ARIMA or other model including dummy variables for the day of the week or for the season of the year.
Re: Forecasting Ridership Data
How is SARIMA done?
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