BUG: Wohngeld Vorrangprüfung

[MImmesberger]

Bug description

If the individual is eligible for both Wohngeld and ALG2/Bürgergeld, Wohngeld has priority if the transfer is at least as high as the ALG2 transfer.

As an approximation for ALG2 eligibility, we currently compare Wohngeld on the household level with ALG2 on the Bedarfsgemeinschaft level in wohngeld_vorrang_hh.

It is, however, possible for some individuals in the household to receive Wohngeld and for some individuals to receive ALG2. The correct priority check (Vorrangprüfung) needs to be done on the individual level. For this, we need to know how the input variables (e.g. Kaltmiete) are broken down from the household to the individual level.

We started to discuss this here.

[MImmesberger]

I have found some terminology that might be useful:

• When household = Bedarfsgemeinschaft (e.g. a married couple living together) we are speaking of "reine Wohngeldhaushalte"
• Whenever household > Bedarfsgemeinschaft where some household members receive Wohngeld and some receive ALG2 we have a "Mischhaushalt". The "Mischhaushalt" consists of the Bedarfsgemeinschaft and exactly one "wohngeldrechtlicher Teilhaushalt". Terminology source

Additionally, this source suggests that Haushaltsmitglieder in the Wohngeld context need to be either related (Parents, children, grandparents, aunt, uncle,...) or need to be an Einstandspartner of one of the family members. If that's not the case, we have two different wohngeldrechtliche Haushalte (even though they may be living in the same apartment).

This suggests for GETTSIM:

• We need to think about what the hh_id exactly indicates. If people living in the same apartment should have different hh_id (because we think of it in the wohngeldrechtlicher context), we should point this out somewhere.
• Grouping Wohngeld on the hh level is wrong. Rather, the grouping should be on a wohngeldrechtlicher Teilhaushalt level.

It's still not entirely clear to me how the Vorrangprüfung works (haven't found anything online). It would make sense if the Wohngeldstelle computes 1) Wohngeld for the whole Wohngeldhaushalt, then 2) compares a "per head" share of the full Wohngeld with the Bürgergeld which then determines which transfer is paid out. This would make sense because the Miet- and Heizkosten are distributed among the household members with the same logic. But so far this is pure speculation.

Edit:

When looking for the Vorrangprüfung of SGB II / Wohngeld you find two different formulations: i) Wohngeld is being paid out once it is higher than the SGB II transfer (e.g. here) and ii) you receive Wohngeld if your Eigenbedarf is gedeckt with it (e.g. here page 4). I just realised that these two requirements should be isomorphic. This implies that GETTSIM should

1. Endogenously determine the Bedarfsgemeinschaften and their SGB II Regelbedarf.
2. Determine who belongs to the wohngeldrechtlicher Teilhaushalt.

• It's simple for the case where the potential wohngeldrechtlicher Teilhaushalt consists of only on BG: Wohngeld is the relevant transfer if the Eigenbedarf of the BG is satisfied with it.
• If there are two BG in one household it's more complicated, because it matters if one or both of them are part of the wohngeldrechtlicher Teilhaushalt. We can't compute Wohngeld for the two BGs separately and compare it with Eigenbedarf because if Eigenbedarf is covered for both of them, the Wohngeld transfer to the resulting wohngeldrechtlicher Teilhaushalt is lower than the hypothetical Wohngeld for the two BGs combined. Not sure what is happening here.

3. Pay out ALG2 for the Bedarfsgemeinschaften that are not part of the wohngeldrechtlicher Teilhaushalt

[MImmesberger]

There is also a calculator for Wohngeld, that works for Mischhaushalte. But the user must specify who is part of the wohngeldrechtlicher Teilhaushalt, so it doesn't help us much here: https://www.bmwsb.bund.de/Webs/BMWSB/DE/themen/stadt-wohnen/wohnraumfoerderung/wohngeld/wohngeldrechner-2023-artikel.html