How has the British class structure changed over the last half century?

Some sociologists at the college where I study (Nuffield) have just published a new paper on how social class mobility in Britain has changed over time. The paper got media coverage in at least four different newspapers, not all of which spun the findings in the same way. (I recommend reading the paper for yourself, or if you can't get access to it, at least the abstract.)

Bukodi et al. (the authors) analysed mobility within four birth cohorts: the 1946 cohort, the 1958 cohort, the 1970 cohort, and the 1980-84 cohort. Building on previous work by Nuffield sociologists, they defined social class in terms of employment relations. In particular, they classified individuals into seven occupational classes, using a modified version of the well known NS-SEC schema:

Classes 1 and 2 of NS-SEC refer primarily to positions in which, to a greater (Class 1) or lesser (Class 2) degree, professional and managerial employees provide service to an employing organization, on the basis of an at least implicitly continuing contract, in return for salaries on an incremental scale, structured career opportunities, and a range of fringe benefits. In contrast, Classes 6 and 7 refer to positions in which, to a greater (Class 7) or lesser (Class 6) degree, employees engaged in more routine tasks sell their labour to an employing organization, on the basis of a contract subject to short-term discontinuation, in return for wages that are related to output or time worked. Classes 3 and 5 then refer to positions defined by employment relations that are ‘mixed’ in the above respects, while Class 4 refers to the obviously quite different positions of self-employed workers and small employers.

Below I plot, for and men and women separately, the distribution of individuals by class at age 27 in each of the four birth cohorts (if you can get past the paywall, see their Tables I-II). Individuals who were not employed at age 27 were classified by Bukodi et al. on the basis of their most recent employment stint.

In the case of men, there has evidently been a rise in membership of Classes 1 and 6, along with a decline in membership of Classes 5 and 7. In the case of women, there has evidently been a rise in membership of Classes 1, 2 and 6, along with a decline in membership of Classes 3, 5 and 7; women's rise in membership of Class 1, and decline in membership of Class 3, are particularly striking.