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Re: st: Counting firms in a panel dataset
From
Nick Cox <[email protected]>
To
"[email protected]" <[email protected]>
Subject
Re: st: Counting firms in a panel dataset
Date
Wed, 15 Jan 2014 19:27:30 +0000
I'd look at data that satisfy
if mean_var1 != 11 & !(var1 == 10/var2 | var1 == 11/var2)
i.e. negating the second condition. Note that if -var1- and -var2- are
both missing, then the second condition
(var1 == 10/var2 | var1 == 11/var2)
reduces to
. == .
which is always true.
Nick
[email protected]
On 15 January 2014 19:18, Miguel A. Duran <[email protected]> wrote:
> Hi, Statlisters. I am using -codebook- to count the number of agents in a
> panel dataset under different criteria. Under a criterion I get 408 agents
> and under another one I get 397. I have an intuition about the cause of this
> difference and I would like to check it out, but I do not know how to do it.
> To help make clear my point, (the relevant part of) my dataset looks similar
> to this,
>
> id startdate date var1 var2 mean_var1
> 1 189 187 10 . 10.75
> 1 189 188 11 . 10.75
> 1 189 189 11 1 10.75
> 1 189 190 11 . 10.75
> 2 192 189 10 . 10.5
> 2 192 190 10 . 10.5
> 2 192 191 11 . 10.5
> 2 192 193 11 . 10.5
>
> Using the command -codebook id if mean_var1 != 11- I get 408 agents, but
> using the command -codebook id if mean_var1 != 11 & (var1 == 10/var2 | var1
> == 11/var2)- I get 397 agents. My intuition is that this happens because
> there are agents (like agent 2) that do not have the observation
> corresponding to the startdate. If I am right adding this requirement to the
> command -codebook id if mean_var1 != 11- should count 11 agents, but I do
> not know how to include that requirement. Will anyone please help with this?
> Thanks in advance.
>
> Miguel.
>
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