st: RE: Calculating growth rates in a panel dataset

 From "Martin Weiss" <[email protected]> To <[email protected]> Subject st: RE: Calculating growth rates in a panel dataset Date Mon, 13 Oct 2008 09:23:57 +0200

```- bys id: g salesgrowth=(sales[_n]-sales[_n-1])/sales[_n-1]-

HTH
Martin

-----Original Message-----
From: [email protected]
[mailto:[email protected]] On Behalf Of Marcus Keupp
Sent: Monday, October 13, 2008 9:17 AM
To: [email protected]
Subject: st: Calculating growth rates in a panel dataset

Dear Statalisters,

please forgive me if the following question seems obvious to you. I have
checked the Statalist
archive and FAQs but answers but found none. My problem is one of data
manipulation in a large
panel dataset. The data ave the following form ("Time of measurement"
refers to the six points in time when the data were collected,
for research design reasons I only use information from periods 3-6)

Panel ID (firm)        Time of measurement                      Sales
103                                3                        3.3million
103                                4                        6.0million
103                                5                        8.2million
103                                6                        8.9million
104                                3                        45.2million
104                                4                        46.5million
104                                5                        43.2million
104                                          6 37.2million

and so on for all panel IDs. What I want to do is to calculate the sales
growth rate for each interval, so that
for each panel ID / time of measurement combination, I have a sales growth
figure. So my desired output would look like this:

Panel ID (firm)        Time of measurement                      Sales
Sales growth in percent
103                                3                        3.3million   .
103                                4                        6.0million
81.81
103                                5                        8.2million
36.66
103                                6                        8.9million
8.53
104                                3                        45.2million
.
104                                4                        46.5million
2.87
104                                5                        43.2million
-7.09
104                                6                        37.2million
-13.88

Unfortunately, I keep running against a wall here. Do you have any
suggestions as to how one could manipulate the data to arrive
at this sales growth variable?

Best regards,
Marcus
___________________________________
Dr. oec. Marcus Matthias Keupp, Dipl.-Kfm.
University of St. Gallen
Institute of Technology Management
Dufourstrasse 40a
CH-9000 St. Gallen / Switzerland
Tel. +41 (0)71 224 7236
Fax +41 (0)71 224 7301
http://www.alexandria.unisg.ch/publications/Marcus_Keupp
*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/

*
*   For searches and help try:
*   http://www.stata.com/help.cgi?search
*   http://www.stata.com/support/statalist/faq
*   http://www.ats.ucla.edu/stat/stata/
```