The Roman institution of patria potestas seems odd enough today even if we look only at the father's direct control over the lives of his children.
However, this is scarcely the extent of the institution. In this part we examine the effects of patria potestas on the interactions of the household with the external world.
As we shall see, paternal power has the potential consequence of bottling up much entrepreneurial energy within the household. In modern societies, children, as they reach adulthood, tend to leave the family domicile and establish themselves elsewhere, earning money and keeping the profits for themselves. This usually renders them independent, or largely so, of their parents, and so they are able to make their own contribution to society. Children retain the rewards of their labor, so the theory runs, and society benefits from increased wealth.The Roman arrangement, though considerably mitigated by high mortality rates, tended to contain youthful energy and discourage individual initiative. However, as we shall see, the arrangement was not without certain advantages. In particular, the household tended to operate within society and the economy as a sort of protocorporation, an economic unit; and the Roman jurists were ingenious in figuring out ways to facilitate this function. Children were an important part of the corporate nature of the household, but the Romans also made extensive use of slaves to the same effect.
We begin with the issue of acquisitions. We are used to the idea that even young children can have an independent estate. A ten-year-old boy who receives a large legacy from an aunt takes the money for himself, even if it is managed by others until he reaches adulthood; a four-year-old movie star earns residuals on her own behalf. By contrast, the children in a Roman household had no independent estates. With only modest exceptions, at law they owned and possessed no property of their own, and this was true no matter how old they were, so long as they remained in the power of a pater familias.
What, then, if third parties transferred property to children or promised to pay them money as a gift or in return for services? The short answer is that the pater familias acquired everything. But this also meant that he was able to use his children (as well as his slaves) as extensions of himself in the amassing of wealth for his household.
In the end, though, one issue you may wish to consider is whether a legal regime such as the Roman one would have been socially tolerable except under conditions of very high mortality. But even if only a fairly restricted number of adults were encumbered with a living pater familias, why wouldn't their plight have led to legal change?