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RE: st: Counting firms in a panel dataset
From
"Miguel A. Duran" <[email protected]>
To
<[email protected]>
Subject
RE: st: Counting firms in a panel dataset
Date
Thu, 16 Jan 2014 12:10:35 +0100
Yes, Nick, I tried something quite similar, and I have just tried what you
propose. If I am not mistaken the reason why it doesn't work is because
-!(var1 == 10/var2 | var1 == 11/var2)- includes observations 1, 2 and 4 for
id1 and all observations of id2. Therefore, both agents are taken into
account under -codebook id if...-
obs id startdate date var1 var2 mean_var1
1 1 189 187 10 .
10.75
2 1 189 188 11 .
10.75
3 1 189 189 11 1 10.75
4 1 189 190 11 .
10.75
5 2 192 189 10 .
10.5
6 2 192 190 10 .
10.5
7 2 192 191 11 .
10.5
8 2 192 193 11 .
10.5
-----Mensaje original-----
De: [email protected]
[mailto:[email protected]] En nombre de Nick Cox
Enviado el: jueves, 16 de enero de 2014 11:51
Para: [email protected]
Asunto: Re: st: Counting firms in a panel dataset
Did you try it? As I understand it, the complement of
A & B
in A is
A & !B
Nick
[email protected]
On 16 January 2014 10:36, Miguel A. Duran <[email protected]> wrote:
> Thanks, Nick, for your answer. I thought of something similar to what
> you propose, but if I am not mistaken it has a problem: I would be
> counting both
> id1 and id2, i.e., I would get again 408 (what I get just using
> -codebook id if mean_var1 != 11-).
>
> 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
>
> -----Mensaje original-----
> De: [email protected]
> [mailto:[email protected]] En nombre de Nick Cox
> Enviado el: miércoles, 15 de enero de 2014 20:28
> Para: [email protected]
> Asunto: Re: st: Counting firms in a panel dataset
>
> 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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