I had long thought that one reason modern developed societies have more gubmnt intervention is that there is a positive income elasticity of demand for gubmnt-provided insurance [i.e. as we become wealthier, we politically demand that the gubmnt look after us more, especially regarding unanticipated negative events].
It turns out there is a strong alternative explanation. According to John Lott, gubmnt intervention in the economy really took off after women were given the right to vote. His analysis is presented in an article in the Journal of Political Economy, and is summarized in his recent book, Freedomnomics:
There is a close relationship between marital status and women's voting patterns — generally, as divorce rates have increased, women have become more liberal. Over the course of women's lives, their political views on average vary more than those of men. Young single women start out being much more liberal than their male counterparts and are about 50 percent more likely to vote Democratic. As previously noted, these women also support a higher, more progressive income tax as well as more educational and welfare spending. But for married women this gap is only one-third as large, and married women with children become even more conservative. But divorced women with children suddenly become 75 percent mor likely to vote for Democrats than single men. [pp. 164-5]Of course, given some recent trends among Republicans in the US (and Conservatives in Canada), it is no longer absolutely clear that Democrats (or Liberals in Canada) are the only interventionists out there.
[and from the footnote to the above quotation] Interestingly, men raising children on their own are only three percent more likely to vote Democratic than single men without children.
digression: I note that Amazon.ca, Amazon.uk, and Amazon.com prices still do not fully reflect recent movements in the exchange rates!