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Unwinding Dependent Variable Transformations

Posted: Tue Jan 26, 2016 10:37 am
by jaylamb20
Hello,

When forecasting from an equation object with a dependent variable specified by expression, EViews gives users the option to forecast the base series or the expression.

For example in "ls d(rx_aud) c ar(1)", EViews will give the option to produce a forecast of RX_AUD or of the differenced series.

Is there are function or proc in EViews for mapping between these expressions and their most basic forms? E.g. I'd like to be able to take predicted values of an expression like "log(rx_aud)-@lag(log(rx_aud),4)" (coming out of a pool estimation) and map them back to predicted values of RX_AUD.

I can hard-code the unwinding of expressions for any specific case, but I'm hoping to write something more general.

Thank you for your help,

-James

Re: Unwinding Dependent Variable Transformations

Posted: Tue Jan 26, 2016 11:14 am
by EViews Gareth
Nope, there's nothing, you'll have to unwind it manually :/

Re: Unwinding Dependent Variable Transformations

Posted: Tue Jan 26, 2016 11:24 am
by jaylamb20
I thought as much but figured it couldn't hurt to ask. Thanks Gareth.

Cheers,

-James

Re: Unwinding Dependent Variable Transformations

Posted: Tue Jan 26, 2016 11:29 am
by EViews Gareth
The internal works that figure out the inverse transformations are black magic. It would be unwise of us to unleash them on the public.

Re: Unwinding Dependent Variable Transformations

Posted: Tue Jan 26, 2016 11:54 am
by jaylamb20
Ha of course, totally understandable. Keep your magic to yourself and I will invent my own.