> I think that it is much more like the US, nowadays.
IIRC, mobility indexes crossed quite a few years ago. IOW, UK is better than the US in this respect. See, e.g., https://en.wikipedia.org/wiki/Global_Social_Mobility_Index, though it's a claim I've read based on other data and before that particular index was compiled.
Social mobility doesn't measure financial welfare and is only weakly correlated with the ability to improve your financial situation. It is largely a measure of wage compression in the economy. If everyone makes similar wages then the population will be highly socially mobile even if those wages are mediocre.
Absolute economic mobility matters much more in terms of having an opportunity to get out of poverty. High economic mobility increases wage variance and therefore naturally reduces social mobility scores since the latter is a relative rank measure.
There are countries where increasing your income $10k makes you "socially mobile" and other countries where increasing your income $50k does not.
It is a maths problem, not one of economic theory, and a well-understood limitation of "social mobility" as a measure in this context. Social mobility between two countries is only meaningfully comparable if their income distributions also have a similar degree of compression since it is a rank statistic. The large differences in wage compression between e.g. Scandinavia and the US are well documented, such as this[0] recent NBER paper, and not controversial.
Increasing rank is much easier than increasing income on a compressed distribution. Being able to easily increase income is much more important than being able to easily increasing rank if you are optimizing for economic opportunity.
Yeah, median income in the UK is about at the level of Mississippi, as is much of Western Europe (Western, not Eastern!). The US is just ridiculously wealthy, and our income inequality is largely a matter of the absurd heights reached at the top, with wide distributions. OTOH, wealth disparity (or even just the perception of wealth disparity) can be politically destabilizing and lead to some pathological social issues. Greater relative social mobility and greater (perceived?) wealth equality seems to result in a better sense of fairness, a sense of fairness is key to social cohesion and trust, and social trust is key to producing wealth. Though, social trust is necessary but hardly sufficient. Likewise, perceived mobility and equality seems necessary but not sufficient for healthy political and civic culture.
That lady has some serious chops, but she said she had to leave the UK, as she was denied opportunities, because of her "Distinctive Northern Accent" (In the UK, the "North" is considered kind of "Redneck," like our South).
IIRC, mobility indexes crossed quite a few years ago. IOW, UK is better than the US in this respect. See, e.g., https://en.wikipedia.org/wiki/Global_Social_Mobility_Index, though it's a claim I've read based on other data and before that particular index was compiled.