I am interested in intergenerational transfers within the family: time transfers like informal long-term care, grandparental childcare, etc; material transfers like bequests and gifts.
There is a large strand of literature about filial obligation, duty etc. I am trying to find theoretical literature opposing to this strand. So, if one of two daughters reduces her working hours and cares for her parents and another daughter does not provide any services, the first daughter should get more money in a form of bequest. So, it is no more about duty, but about informal payments for services in the family. I would be very thankful for your help!