Dear All,

I am quite new to STATA and need your help. I am currently doing my master thesis and would like to know how to merge cross-sectional studies recorded in different years to one file. I tried to use dataex command but did not succeed. So basically, in the cross-sectional study, the respondents vary year by year therefore I tried to merge my files based on countries. However, when I tried to merge the first two years, the second year overwrote the first year, meaning I got only the values from the second year. As the respondent can be from the same country, one country appears several times in my dataset. Therefore I tried the command merge m:m.

I hope my situation is clear. Thank you so much for helping me out!

PS: Here is the dataex but I am not sure if it is useful:

* Example generated by -dataex-. To install: ssc install dataex
clear
input double(country setid)
1 1161000043
1 1161000104
1 1161000111
1 1161000385
1 1161000442
1 1161000507
1 1161000601
.......
end
label values country country
label def country 1 "United States", modify
[/CODE]
------------------ copy up to and including the previous line ------------------

Listed 100 out of 194824 observations
Use the count() option to list more

Here is the link to the database: https://www.gemconsortium.org/data/sets?id=aps ( GEM 2016 APS Global Individual Level Data)