Unity has an interesting but, I think, mistaken post at Liberal Conspiracy on the data surrounding illegitimacy and other measures of the breakdown of the traditional family. His argument is, essentially, that the economic hardship of Thatcher's early years (the early eighties) was the major cause of a rise in non-traditional families rather than social changes associated with the sixties.
I'll deal quickly with a side-issue Unity discusses, teenage pregnancy, before moving on to the problems with his analysis of the data on illegitimate children. If I have misconstrued anything he has said, or missed where he has dealt with a problem I raise, then I hope someone will correct me. His language is rather dense, his post rather long and the hour rather late.
Teenage pregnancy
Unity's point on this issue is that the number of teenage pregnancies hasn't changed and, thanks largely to abortion, the number of teenagers becoming parents has fallen. I think the implication is that the case there is a particular contemporary problem with teenage pregnancies is weak.
It is important to note, first, that it isn't only social conservatives who believe that we have a problem with teenage pregnancies. It is a problem I've seen people across the ideological spectrum identify and is, therefore, actually a rather centrist 'received wisdom'.
The problem Unity identifies isn't the actual analysis but the term 'teenage pregnancy'. What people are actually getting at when they use the term teenage pregnancy is a pregnancy that is significantly earlier than the societal norm. Back when the average age at which women had their first child was much younger a pregnancy in the teenage years was more similar to a standard (early twenties) pregnancy. Now it is very significantly different and, therefore, clearly has much more capacity to be disruptive to the life of the mother, extended family and community.
The Lag
Instead of drawing a graph of the number of illegitimate children born, as Unity did, I've gone for the percentage of children born illegitimate. Throughout the period at study total birth rates were falling and we don't want that change to contaminate our data. I've used Eurostat figures, because having comparable statistics for other countries will come in handy later.
Live births outside marriage as a fraction of total births, UK
While the early eighties looks less abnormal than it did in Unity's graph it is still the most obvious break in the trend. However, that doesn't mean that some event in the eighties, like Thatcher's economic liberalism, caused rising illegitimacy. Social changes, of the sort that happened in the sixties, could clearly need years to take effect. It seems entirely plausible that there was a lag.
I think Unity discounts that possibility on these grounds: It isn't the case that any change that is lagged must also be gradual. A classic example of a hypothesis that a problem would take several years to emerge and then erupt all at once was variant-CJD. We had all eaten the burgers that were going to kill us but the disease would take some time to come through. At some point in the future the variant-CJD rate would start to grow rapidly. In other contexts this has been called a 'hockey stick'.
"Well its not the kind of cohort effect that we would expect if the cause were some sort of generation effect arising out of the growth of the so-called permissive society, such a change should bleed through into the data in stages, giving the same kind of staggered pattern we saw in the data for births within marriage during the 80s and early 90s, a pattern that simply isn’t there."
It seems quite plausible that cultural changes in the sixties appear - looking back on it all from 2008 - to change norms immediately but, away from the spotlight, progressed more slowly. It seems entirely likely that it would take decades for people to really feel confident that social norms had changed.
In short, there is no reason why the graph above cannot be reconciled with the 'social conservative' understanding of the breakdown in the traditional family. However, it clearly could also be reconciled with Unity's analysis that it was Thatcher's economic policies which made the difference. We need more evidence to settle the issue. Fortunately, I have some.
An international comparison
I think that the easiest way of falsifying the "it was Thatcher" hypothesis is to look at evidence from other countries. Thatcher did not implement liberal economic policies internationally. I've chosen a few countries from the EU-15 pretty much at random. It wouldn't be hard to study all the Western European countries but I don't think it is necessary to illustrate my point so I'll leave that for today.
In Belgium there is also a take-off in the early eighties, though illegitimacy remains less frequent than in the UK.
Live births outside marriage as a fraction of total births, Belgium
In Germany the pattern is similar, the beginnings of a take-off in the early eighties, but there is a dip in the early nineties. That dip is probably the result of reunification.
Live births outside marriage as a fraction of total births, Germany
Spain also takes off in the early eighties.
Live births outside marriage as a fraction of total births, Spain
Sweden's pattern doesn't have such a clear take-off. If one did occur it looks like it happened in the early seventies. I'm not sure what to make of that really.
Live births outside marriage as a fraction of total births, Sweden
So, unless we seriously think that all these countries had something akin to Thatcherism rise to political prominence in the early eighties (or early seventies) it would appear that the rise in the number of births outside wedlock was not caused by Thatcher. It seems far more likely that cultural changes across the West are the driving factor (albeit with a significant lag).
Of course, there could be a third explanation.
Analysis
In the end, out of wedlock and teenage pregnancies are highly imperfect proxies for the real problem social conservatives (or, labrador conservatives) seek to address, the number of pregnancies among those who are either not committed or able enough to raise children. As such, the empirical debate above cannot settle the broader issue.
Dalrymple and Bloom, among others, set out a powerful case that intellectual and cultural changes in recent decades have had serious effects on Western society. On the quality of our intellectual life, the wellbeing of our children and the decency of our behaviour when we interact. There are certainly alternate explanations for many of the problems they identify but "Thatcher did it" just isn't a credible response.
The early years of Thatcher's government were tough. A reckoning with the decline of Britain's old staple industries had been delayed too long and was exceptionally unpleasant. The associated hardship may well also have exposed the earlier weakening of social structures that are most important when times are hard. That doesn't mean that Thatcherite economic policies weren't necessary in order to enjoy the revival that we have been experiencing since; an end to long decades of relative decline. Liberal economic policies, essential to our economic renaissance, did not create our social crisis.