The domestic problems facing modern politicians – the decay of the two-party system, calls for the breakup of Britain and deepening apprehension about a disaffected ‘underclass’, not least that part made up of alienated young Muslims – are symptoms of a political order less secure than at any time since the Second World War. While it would be ridiculous to attribute the entire blame for support for anti-establishment political parties or urban riots to a lack of upward social mobility, perceptions of blockages to mobility, as part of a wider disappointment of prospects for improving social and material conditions, have become an important part of a toxic mix in which discontent festers.

What matters is not that upward mobility is a realistic likelihood but that people believe it to be. If mobility were happening in a loosely meritocratic way, it could be seen as ‘fair’. The hope of upward mobility – if not for oneself, then for one's children – makes mobility a potent source of political legitimacy. Mobility plays a significant role in social discontent when it is seen as either unlikely or based on unequal opportunities. It is therefore a political issue; not only in the narrow sense of parties, manifestos and elections, but also in how people believe societies should function. The contemporary electoral challenge of nationalist parties is only the latest version of the difficulty all ruling classes have in persuading those they rule to accept the legitimacy of the status quo.

Mobility therefore needs to be not only clearly defined and measured, but also understood in a wider framework of social thought: contemporary ideas about mobility have roots in earlier conceptualisations of the political process. The evolution of ideas about mobility extends from questions in classical Greek philosophy about the role of rulers, through the Enlightenment and attempts to account for the emergence of a more secular, post-agricultural society, into early fascism and on to US foreign policy. This inheritance has influenced the work of mobility analysts and the ways in which their findings have trickled out to be consumed in new forms in the public consciousness.

Mobility in political philosophy and history

Changes in membership of hierarchical political groups were debated long before the term ‘social mobility’ was first introduced in the mid 1920s (Random House Dictionary 2011).