Freedom to Breed Is Intolerable
The tragedy of the commons is involved in population problems in another way. In a world governed solely by the principle of "dog eat dog" --if indeed there ever was such a world--how many children a family had would not be a matter of public concern. Parents who bred too exuberantly would leave fewer descendants, not more, because they would be unable to care adequately for their children. David Lack and others have found that such a negative feedback demonstrably controls the fecundity of birds.  But men are not birds, and have not acted like them for millenniums, at least.
If each human family were dependent only on its own resources; if the children of improvident parents starved to death; if thus, over breeding brought its own "punishment" to the germ line -- then there would be no public interest in controlling the breeding of families. But our society is deeply committed to the welfare state,  and hence is confronted with another aspect of the tragedy of the commons.
In a welfare state, how shall we deal with the family, the religion, the race, or the class (or indeed any distinguishable and cohesive group) that adopts over breeding as a policy to secure its own aggrandizement?  To couple the concept of freedom to breed with the belief that everyone born has an equal right to the commons is to lock the world into a tragic course of action.
Instead of looking at the world and this issue as it deals with the world, lets just look at the issue as it applies to the United States..... The United States has lost its way, and our system is creating less people who care and more people who plunder....
Conscience Is Self-Eliminating
It is a mistake to think that we can control the breeding of mankind in the long run by an appeal to conscience. Charles Galton Darwin made this point when he spoke on the centennial of the publication of his grandfather's great book. The argument is straightforward and Darwinian.
People vary. Confronted with appeals to limit breeding, some people will undoubtedly respond to the plea more than others. Those who have more children will produce a larger fraction of the next generation than those with more susceptible consciences. The differences will be accentuated, generation by generation.
In C. G. Darwin's words: "It may well be that it would take hundreds of generations for the progenitive instinct to develop in this way, but if it should do so, nature would have taken her revenge, and the variety Homo contracipiens would become extinct and would be replaced by the variety Homo progenitivus. 
The argument assumes that conscience or the desire for children (no matter which) is hereditary-but hereditary only in the most general formal sense. The result will be the same whether the attitude is transmitted through germ cells, or exosomatically, to use A. J. Lotka's term. (If one denies the latter possibility as well as the former, then what's the point of education?) The argument has here been stated in the context of the population problem, but it applies equally well to any instance in which society appeals to an individual exploiting a commons to restrain himself for the general good -- by means of his conscience. To make such an appeal is to set up a selective system that works toward the elimination of conscience from the race.
What are we to do...... How do we turn the tide? How do we Manage the commons?