# Re: st:how to create yearly lag in monthly data?

 From "Michael S. Hanson" To statalist@hsphsun2.harvard.edu Subject Re: st:how to create yearly lag in monthly data? Date Tue, 2 May 2006 15:59:41 -0400

```On May 2, 2006, at 2:24 PM, Badri wrote:

```
```Dear Stata users and experts,
I'm dealing with a monthly data for a few years.
Let me denote month no., by m and year no., by y.  What I need to do
is to generate a variable B{m,y}=A{m,y-1}. A is a variable that is

This sounded quite simple to me till I tried a lot in vain.

Could anyone give a solution for this simple problem?
```
Assuming your data are -tsset- at a monthly frequency, you can use the lag operator: L12.a will give you the 12-month (i.e. one-year) lag of the variable 'a'. Additional information is available in [U] 11.4.3, or (in Stata 9.2) type -hsearch lag operator-. HTH.

-- Mike

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