Population management is not a euphemism for population control.  In a society that has chosen to move toward social stability, population management is near the top of social, political and economic/financial concerns.  While having sex expresses a highly private and intimate relationship, the consequences in births are shared with the rest of society.  In reality what seems so private becomes a shared obligation and responsibility of everyone in a society that supports social sustainability.  The situation becomes more grievous when social and material resources become more and more scarce.  In a society that is moving toward social sustainability few if any person would voluntarily decrease their quality of life or any opportunities to develop their innate potential equally with another person being added to the population.  The inverse relationship between social and material resources and an increasing population is not readily apparent to short-lived humans, but in the term of a society that has the potential to endure for centuries and millennia, that inverse relationship becomes critical. 

Population management – Every person’s responsibilities.  Unrestrained population growth reflects the highly undisciplined nature of most democratic societies at the level of the individual.  Whether we are aware of it or not, when children are born that child becomes everyone’s obligation and responsibility.  This moral truth is as valid in today’s nations as it will be in a socially sustainable nation.  When a family increases over the size of 3, every added child shares the social and material resources with everyone else, as though those resources were unlimited, and everyone in the nation agreed to it.  If you want a view of the reality of limited social and material resources upon large families, see BBC World News for its coverage of the emigrants from Syria. 

In a society that is moving toward social sustainability, the personal responsibilities of reproductive individuals is to limit their reproduction to the number needed to replace them.  This maintains the steady and stable state of the population necessary to sustain society, but not so much that the resources of society are overwhelmed. 
If that is the socially sustainable moral responsibility of reproductive individuals, what is the moral responsibility of society, and the organizations that support society?