James Manzi writes,

The level of family disruption in America is enormous compared to almost every other country in the developed world. Of course, out-of-wedlock births are as common in many European countries as they are in the United States. But the estimated percentage of 15-year-olds living with both of their biological parents is far lower in the United States than in Western Europe, because unmarried European parents are much more likely to raise children together. It is hard to exaggerate the chaotic conditions under which something like a third of American children are being raised — or to overstate the negative impact this disorder has on their academic achievement, social skills, and character formation. There are certainly heroic exceptions, but the sad fact is that most of these children could not possibly compete with their foreign counterparts.

…In a nation where about 40% of births occur outside of wedlock, many children will be left behind. Nonetheless, schools remain one of our primary policy instruments for enhancing both social mobility and our competitive position. They are essential to the task of balancing innovation and cohesion…We now need a new vision for schools that looks a lot more like Silicon Valley than Detroit: ­decentralized, ­entrepreneurial, and flexible.

…we should think of immigration as an opportunity to improve our stock of human capital. Once we have re-established control of our southern border, and as we preserve our commitment to political asylum, we should also set up recruiting offices looking for the best possible talent everywhere: from Mexico City to Beijing to Helsinki to Calcutta. Australia and Canada have demonstrated the practicality of skills-based immigration policies for many years. .. It would be great for America as a whole to have, say, 500,000 smart, motivated people move here each year with the intention of becoming citizens.

His essay dwells on the theme that economic innovation threatens social cohesion, a theme that can be found in Schumpeter, Fukuyama, Brink Lindsey, and no doubt many others.

I find the issue interesting, but I find that I have little to say. I think that I know what economic innovation is, what its benefits are, and some of the conditions that foster and impede it. Book 1 (with Nick Schulz) reflects my thinking there.

But I do not know exactly what we mean by social cohesion. I mean, if you have a civil war, that would seem to represent a loss of cohesion, and clearly civil wars are very bad things. But beyond that, the concept has a vague, “I know it when I see it” connotation.

I think libertarians need to take a stand on the topic of social cohesion. If we do not think it is important, we have to say why. If we think that it is best promoted by libertarian means, we should say how. Serious people like James Manzi worry about social cohesion, so I think we owe them a response.

Note: WIll Wilkinson seems to be making social-cohesion arguments near the end of his post.