Hello,

I would like to convert wide to long format to create a panel data set, so that each 'Country' has 'month' variable '198501', '198502', 198503, .... 200203.
Here the X'01' means X'January', X02 is X'Febuary', and so on.

Here is a part of the dataset (I cut some because it is very long)
Code:
* Example generated by -dataex-. To install: ssc install dataex
clear
input str4 year str30 Country double(X01 X02 X03)
"1985" "OPEC"                                       700                 612                  97
"1986" "OPEC"                                      1684                1044                 703
"1987" "OPEC"                                       605                1073                 665
"1988" "OPEC"                                     767.3              1097.6                 571
"1989" "OPEC"                         967.6000000000001   858.4000000000001              1136.5
"1990" "OPEC"                                    2638.5  1962.8999999999999  1890.8000000000002
"1991" "OPEC"                                    1978.6  1226.3999999999999               856.5
"1992" "OPEC"                                     760.3  387.60000000000014   409.3000000000002
"1993" "OPEC"                                    1123.3                 974              1049.2
"1994" "OPEC"                         360.2000000000003   647.3000000000002   683.4000000000001
"1995" "OPEC"                         848.1000000000001  1373.6000000000001  1423.8000000000002
"1996" "OPEC"                                    1767.8              1237.4              1020.2
"1997" "OPEC"                                      2343              1551.8                1327
"1998" "OPEC"                                       876               612.3                 432
"1999" "OPEC"                                    1008.5   428.2000000000003   659.6000000000004
"2000" "OPEC"                                    2897.4              3121.4  3996.3999999999996
"2001" "OPEC"                        4088.1000000000004  3298.2999999999997              3355.5
"2002" "OPEC"                                    2495.1  1949.8999999999999  2466.8999999999996
end
I want to convert from wide to long creating a 'month' variable.

Thank you always for your help!!