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mix of dynamic and static forecast
Posted: Wed Nov 30, 2011 3:24 am
by kiber_master
Hello!
Could you explain, why in my sample for dynamic forecast EViews use values of dependent variable on the forecast period?
In the workfile y is a serie that have values on the forecast period (2012-2020), y1 is a serie that have no values on the forecast period
Re: mix of dynamic and static forecast
Posted: Wed Nov 30, 2011 9:29 am
by EViews Gareth
You don't say what period you forecasted over...
But if you forecast from 2000-2030, you'll get forecast values up until 2010, which is the last period for which you have data for your independent variable. Obviously you cannot forecast for periods for which your X variable has no data.
Re: mix of dynamic and static forecast
Posted: Wed Nov 30, 2011 11:09 pm
by kiber_master
the forecast period (2012-2020), it was said
Re: mix of dynamic and static forecast
Posted: Thu Dec 01, 2011 8:45 am
by EViews Gareth
Sorry, I must be blind. Anyway, my answer remains the same.
Re: mix of dynamic and static forecast
Posted: Fri Dec 02, 2011 12:31 am
by kiber_master
Your answer is clear, but I can't understand, why I suddenly get the forecast on 2013-2015. For dynamic case and for variable y it shouldn't be at all, because we can't calculate forecast on 2012 (using ar(1), 2011 is missed). But if there is a value at 2012 for y, the forecast is calculated. I think, it isn't a dynamic forecast, because it shouldn't take into account 2012 actual value, only fitted by the model.
If I explained smth not very clear, please, give me a sign!
Thank you
Re: mix of dynamic and static forecast
Posted: Fri Dec 02, 2011 8:58 am
by EViews Gareth
I don't get a forecast for 2013-2015, so I don't know.
Re: mix of dynamic and static forecast
Posted: Mon Dec 05, 2011 3:12 am
by kiber_master
So, if you:
1. Open the attached workbook.
2. Open equation tsls.
3. Estimate y c x1 ar(1) (x2 - instrumental, const and lagged vars added) for a period 1980-2011.
4. Click forecast and set forecast dates for 2012-2030.
5. Deselect option "Insert actual values...".
6. Calculate forecast.
the variable yf wil be empty?
Re: mix of dynamic and static forecast
Posted: Mon Dec 05, 2011 7:37 am
by startz
I do get a forecast for 2013-2015. Since you have X1 from 2011-2015 this is as it should be I think.
Re: mix of dynamic and static forecast
Posted: Tue Dec 06, 2011 2:57 am
by kiber_master
But there is ar(1). So, the value at 2013 depend on forecasted y at 2012, but it is empty.
Re: mix of dynamic and static forecast
Posted: Tue Dec 06, 2011 7:32 am
by startz
But there is ar(1). So, the value at 2013 depend on forecasted y at 2012, but it is empty.
I think you're confusing y - yforecast with y-x*beta. The former requires the lagged residual, the latter doesn't. At least I think that's what's going on.
Re: mix of dynamic and static forecast
Posted: Wed Dec 07, 2011 12:19 am
by kiber_master
There shouldn't be any y for dynamic forecast. Dynamic means using only forecasted values, like yforecasted-x*beta, doesn't it?
Re: mix of dynamic and static forecast
Posted: Wed Dec 07, 2011 7:33 am
by startz
I don't think this is right. Dynamic forecasting refers to forecasting out the y. The AR(1) comes from forecasting out from the last observed residual.
Re: mix of dynamic and static forecast
Posted: Thu Dec 08, 2011 8:55 am
by kiber_master
I think it is not correct to use values out of the sample periods we set in equation. What if I don't want to use them for calculation bu check them with forecasted? This behavior is inconsistent, because, if there is no missing values at the end of the sample, to calculate y_forecasted(2013) you use y_forecasted(2012), not y_actual(2012). It isn't understandable for me(
Re: mix of dynamic and static forecast
Posted: Thu Dec 08, 2011 10:02 am
by EViews Gareth
If you ask EViews to do a dynamic forecast, then EViews will use actual values of Y(-1) for the first forecasted period. It has to do that, other wise you'd never be able to do a dynamic forecast.
I believe what you're questioning is the fact that if Y(-1) isn't available for the first forecasted period, EViews will automatically move the forecast sample up until it does have a valid, actual, value for Y(-1). When EViews does this, and you are doing the forecast interactively, you can spot it from the fact that EViews tells you that it adjusted the forecast sample. If you're doing it in a program, though, there is no way to know, which is unfortunate.
Re: mix of dynamic and static forecast
Posted: Thu Dec 08, 2011 9:30 pm
by kiber_master
Thank you for the explanation! Now all is clear for me!