[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

st: help levpet

From   pim de Nijs <>
Subject   st: help levpet
Date   Thu, 11 Dec 2008 17:29:57 +0100

My knowledge about Stata is limited and a feel ashamed that i have to bother you with my question because maybe I just made a stupid mistake in the command that I use. But I really do not know how I can solve the problem and I could not find a solution on the internet.  
I want to use the following command:
. levpet logSales, free(logEmployees ) proxy(logMaterials) capital(logCapital) i(number) t(Year) revenue 
I get the following error:
repeated time values within panel

I have no idea why i get the ''repeated time values within panel'' error. I am 100% sure that there are no duplicates:
. dupliactes list Year number
result: no observations are duplicates
By only using a part of my dataset i get an idea what the problem is:
. levpet logSales if (NACE<=1531), free(logEmployees ) proxy(logMaterials) capital(logCapital) i(number) t(Year) revenue 
Now I get the results of the levpet command. However there is something strange:

Dependent variable represents revenue.          Number of obs      =       148
Group variable (i): number                                   Number of groups   =      5756
Time variable (t): Year
                                                               Obs per group: min =         1
                                                               avg =       4.1
                                                               max =         5

The number of observations is 148 and the number of groups is 5756? Then I see that the average number of observations per group is 4.1 This means that the number of groups should be 36 and not 5756.
I really have know idea what is going wrong. I just like to get the levpet results for my whole dataset. The . help levpet command do not give me the answer. Others papers that I have read and that are using the levpet command are telling that it is straightforward to use the levpet command. 
Can someone help me
Yours sincerely
Download de nieuwste emoticons voor in je Messenger

*   For searches and help try:

© Copyright 1996–2017 StataCorp LLC   |   Terms of use   |   Privacy   |   Contact us   |   What's new   |   Site index