My girlfriend and I are thinking about marriage and having children and I have spent the last days trying to figure out concepts how to handle finances from that point forward. I believe that this is relevant to most people in such a situation not only for us personally.
Our situation is as follows:
- I make about 3200€ net per month (45h) and my girlfriend makes 2200€ net per month (38,5h). She has a Master's in Biology, I have a PhD in Computer Science.
- Currently we split all common costs in half (rent, food, gas etc.).
- Each of us spends about 1200-1400€ per month (including the aforementioned common costs).
- Each child will cost about 300€ per month (considering that we also get "Kindergeld").
- After parental leave my girlfriend will likely work part time, making about 1100€ (so not even covering her own costs), while will make 3800€ due to different taxation.
- Both of us feel very strongly about being financially independent and if possible we both don't want to take money from each other.
- The ultimate goal for both of us is to work full time, but surely this will not be possible at first.
Now I have been trying to figure out how to split the money that we both earn. From what I can see there are several concepts but none of them really seems ideal to me.
- Determine the income ratio (currently 1.73, later 3.2) and pay bills according to this ratio. (She will pay less but also have much less money left over for savings.)
- Put all the money in a big pot, pay the bills, and split the rest. (I would basically be giving her more money than necessary to pay the bills. Seems kind of unfair since I have invested a lot more time and money in my education and also have a more stressful job.)
- I pay all running costs and she gets to keep whatever she makes. (Unfair because she would actually have much more money left over than me.)
- Determine the income ratio before kinds with respect to the same hours (i.e. what would each if make if we worked 40h). Then distribute the income after kids so that this ratio is kept and a) pay bills 50:50 or b) pay bills according to resulting ratio (about 60:40). This seems to be the fairest in my opinion but it drastically lowers the motivation for both of us the increase our own income, while it increases the motivation for each of us to have the partner’s income increased. So this could lead to conflicts.
- Pay everything 50:50. (Not possible due to low income in part time.)
- We both pay for our own costs and split the costs for the children according to the ratio. (Not possible due to low part time income.)
So my question is: Are there any guides or studies on how to proceed in such a situation? I am well aware that there are different opinions on this subject but I am interested in actual concepts and also studies on how such concepts work out in the real world.
Edit: We are living in Germany, so we can get a combined of 14 months "paid" parental leave ("paid" because only a fraction of the actual income is paid). Each month she would receive about 1450€ and I would get 1800€. The cost for child care varies greatly, so I have no good estimate for that yet.