Stata The Stata listserver
[Date Prev][Date Next][Thread Prev][Thread Next][Date index][Thread index]

RE: st: xtabond and 'no observations'


From   "Monica L. Parra Torrado" <[email protected]>
To   <[email protected]>
Subject   RE: st: xtabond and 'no observations'
Date   Tue, 7 Dec 2004 13:21:47 -0500

Hi Jo,
I had that problem once.  What you have to do is generate a new time
variable to avoid r(2000) (no observations error) and tsset using this new
one.  
For example: (notice that d73 to d98 are time dummies)

gen time2 =. ;

replace time2 = 1 if d73 == 1 ;
replace time2 = 2 if d78 == 1 ;
replace time2 = 3 if d83 == 1 ;
replace time2 = 4 if d88 == 1 ;
replace time2 = 5 if d93 == 1 ;
replace time2 = 6 if d98 == 1 ;

tsset panchayat time2 ;

Hope it works for you.

Best,


Monica L.


-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of jyotsna puri
Sent: Monday, December 06, 2004 7:32 AM
To: [email protected]
Subject: RE: st: xtabond and 'no observations'

Hi all,

I am obviously not seeing something.

I have a dataset for a land variable (sr1tara), water(agwsc2), credit 
(crbadu1).
There are 'id' variables for villages and unbalanced data is present for
6 years (maximum). I have tried to use the xtabond command and I get
'no observations'. There is some thing that I am obviously carelessly
missing. Can someone help me out?

At the minimum I do the following (output below).
My questions:
1. Why am I getting 'no observations'?

2. Is this anything to do with the fact that my data is not balanced?
(Shouldnt be. The abdata.dta - the example dataset provided by stata
for xtabond is also unbalanced). I have obviously used other variables
in other commands but it dosent work for even this minimal list...

3. This may have something to do with the note after 'tsset' which
says I have data from 86 to 96, but with gaps.

I have two types of 'missingness'. This is an unbalanced
data - so all villages are not present for
all years. I have tried xtabond for villages that are only present
for all 6 years. No avail.

There is also 'item non-response' i.e the village may be
present but data for sr1tara is missing. I have tried
two options. In the first, filling up with tsfill, full.
In the second throwing out these observations
completely, and then filling up with tsfill, full.

I have also tried replacing 'missing' values
of sr1tara with zeros and then using the command.
No avail.

-Jo

[Output follows:]
. clear
. use forestall
. tsset id year
       panel variable:  id, 13010704 to 13241610
        time variable:  year, 86 to 96, but with gaps
. xtabond sr1tara l(0/1).popn
no observations
r(2000);
. bys year: summ sr1tara popn
----------------------------------------------------------------------------
---
-> year = 86
    Variable |       Obs        Mean    Std. Dev.       Min        Max
-------------+--------------------------------------------------------
     sr1tara |       237    145.5053    193.1498         .5     1322.5
        popn |       357     597.112    379.3441         96       2779
----------------------------------------------------------------------------
---
-> year = 88
    Variable |       Obs        Mean    Std. Dev.       Min        Max
-------------+--------------------------------------------------------
     sr1tara |       364     115.408      250.62          0       2510
        popn |       380    593.3526    369.2651         70       2091
----------------------------------------------------------------------------
---
-> year = 90
    Variable |       Obs        Mean    Std. Dev.       Min        Max
-------------+--------------------------------------------------------
     sr1tara |       358    124.3645    233.3991          0       1725
        popn |       414    569.6667    366.6383         74       2774
----------------------------------------------------------------------------
---
-> year = 92
    Variable |       Obs        Mean    Std. Dev.       Min        Max
-------------+--------------------------------------------------------
     sr1tara |       353    136.8555    270.5674          0       2760
        popn |       449    554.1626    372.1043         75       2832
----------------------------------------------------------------------------
---
-> year = 94
    Variable |       Obs        Mean    Std. Dev.       Min        Max
-------------+--------------------------------------------------------
     sr1tara |       231     172.131    249.4894          1       1729
        popn |       472    567.5742    372.0968         63       2897
----------------------------------------------------------------------------
---
-> year = 96
    Variable |       Obs        Mean    Std. Dev.       Min        Max
-------------+--------------------------------------------------------
     sr1tara |       271    157.5424    258.6707          0       2000
        popn |       501    544.4032    338.6604         61       2297



Jyotsna (Jo) Puri
[email protected]
Doctoral candidate, University of Maryland at College Park,
Maryland.


*
*   For searches and help try:
*   http://www.stata.com/support/faqs/res/findit.html
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/


*
*   For searches and help try:
*   http://www.stata.com/support/faqs/res/findit.html
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/



© Copyright 1996–2024 StataCorp LLC   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index