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From |
Nick Cox <njcoxstata@gmail.com> |

To |
"statalist@hsphsun2.harvard.edu" <statalist@hsphsun2.harvard.edu> |

Subject |
Re: st: Weighted moving sum missing values |

Date |
Mon, 24 Jun 2013 19:27:41 +0100 |

The presumption that missing means zero is a very strong one but I am trusting that there is a very, very strong defence. That said you just need terms such as cond(missing(L1.var1), 0, L1.var1) rather than L1.var1 Alternatively, why not work with a clone clonevar fudged_var1 = var1 replace fudged_var1 = 0 if missing(var1) Nick njcoxstata@gmail.com On 24 June 2013 18:59, Dorian Garbe <dorian.garbe@gmail.com> wrote: > I have panel data with panel variable: Id and time variable Yr which > looks as follows: > > Yr Id Var1 Var2 > > 2002 1 0 ... > 2002 2 3 ... > 2003 1 4 ... > 2003 2 0 ... > 2004 1 1 ... > 2004 2 5 ... > > Var 2 is supposed to be the cumulated sum of Var1, weighted and over > the past five years. > However if I just use gen by Id: Var2= 1*L1.Var1 + 0.8*L2.Var1 + > 0.6*L3.Var1 + 0.4*L4.Var1 + 0.2*L5.Var1 for 2002-2006 this will > generate a missing value, because not all 5 lagged variables are > available. I would like to treat this missing lagged variables as 0 or > just ignore them, so for 2004, Id 1 the value is calculated as Var2= > 1*L1.Var1 + 0.8*L2.Var1 = 1*4 + 0.8*0 > I also need to do this by Id. > > Could I do some sort of nested if, saying If Yr=2002 then Var2=0, if > Yr=2003 then Var2=L1.Var1, if Yr=2004 then Var2= L1.Var1 + 0.8 L2.Var1 > ....? I think you cannot do this in Stata!? > > I have been searching for a solution all day, but could not really > figure it out. I am also an absolute beginner. > * * For searches and help try: * http://www.stata.com/help.cgi?search * http://www.stata.com/support/faqs/resources/statalist-faq/ * http://www.ats.ucla.edu/stat/stata/

**References**:**st: Weighted moving sum missing values***From:*Dorian Garbe <dorian.garbe@gmail.com>

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