Patriarchal? Where's the evidence of that? Who said father's are deciding on a boy? It seems mothers are just as adamant to favor a boy and are thus just as willing to engage in the abortion.

Patriarchal motivations are different from sex selection favoring boys.

Good point, but living in a patriarchal culture where male babies mean more security would influence sex selection, even by women. Patriarchy is promoted and maintained by all members of the society. Sure it may not be the men choosing to perform sex-selective abortions, but it's still a patriarchal decision. And they may well have more decision making power in a patriarchy, since they would most likely be the primary breadwinners. If their desires aren't met, they could leave or have lower work performance and thus endanger the woman's safety and survival.