Before revision:  But resources are often allocated to groups, such as families or countries, whose members consume the same bundle but have different preferences. Do fair and efficient allocations exist in such an "economy of families"? We adapt three common notions of fairness: fair-share, no-envy and egalitarian-equivalence , to an economy of families.
After revision:  But resources are often allocated to groups, such as families or countries, whose members consume the same bundle . Families are our lead example: the father, mother and children get to consume the same garden, kitchen, and vacations. We adapt each of the three most popular principles of fairness: fair-share, no-envy and egalitarian-equivalence , to an economy of families.