Birthplace variable in ppathl

Dataversion

SOEP Core v41i

Data Set

ppathl

Please describe your problem

Hi everyone,

I am currently using the variable birthregion_ew in ppathl (https://paneldata.org/soep-core/datasets/ppathl/birthregion_ew) and have a question about its coding.

The vast majority of observations are coded as „[-2] Does not apply“.

. tab birthregion_ew

       Birth place: German Federal Land |
                    (East-West Version) |      Freq.     Percent        Cum.
----------------------------------------+-----------------------------------
[-5] Not included in this version of th |     17,521        1.20        1.20
                    [-2] Does not apply |    938,857       64.13       65.32
                         [-1] No answer |     39,740        2.71       68.04
                      [21] West-Germany |    325,879       22.26       90.30
                      [22] East-Germany |    142,075        9.70      100.00
----------------------------------------+-----------------------------------
                                  Total |  1,464,072      100.00

Could someone help clarify why so many observations receive -2 on this variable? I also cross-checked this against country of birth and found that some respondents who were born in Germany are also coded as -2 in birthregion_ew.

. tab birthregion_ew if corigin == 276

       Birth place: German Federal Land |
                    (East-West Version) |      Freq.     Percent        Cum.
----------------------------------------+-----------------------------------
[-5] Not included in this version of th |      2,776        0.25        0.25
                    [-2] Does not apply |    610,286       54.48       54.73
                         [-1] No answer |     39,271        3.51       58.23
                      [21] West-Germany |    325,837       29.09       87.32
                      [22] East-Germany |    142,067       12.68      100.00
----------------------------------------+-----------------------------------
                                  Total |  1,120,237      100.00

Does anyone have ideas why it might be the case?

Many thanks in advance!

Cheong