Pointer variables not present in samples from Germany (1971, 1981 and 1987)

I can’t figure out why in the samples from Germany (1971, 1981 and 1987) the pointer variables are not present (parrule, stepmom, etc). I have seen that in the countries in which the observations are not grouped into households, these variables can´t be constructed. But it is not the case in Germany in those years. I´ve been looking at the technical documents but I couldn´t find the answer.

For Germany (1971, 1981 and 1987), MOMLOC, POPLOC, and SPLOC are available for identifying relationships, however the more complex family interrelationships (such as STEPMOM etc.) are not. This is likely because of the lack of a RELATE variable within the data IPUMS received. Without this variable to describe individuals’ relationships to the head of the household, it is very difficult to infer these more complex relationships with any sort of certainty.

I hope this helps.

Thanks Joe, now it´s clear!