DS is just about to complete an economics PhD in the US .
He was actually offered funding for a PhD in the UK but was strongly advised to take a US offer (similarly ranked departments) to add breadth to his education and networks, and because of the different structure on the PhD. (6 years funding whereas I think in the UK it would have been three years.) Oddly financially he would have been better off in the UK as he would have been paid extra for any teaching or research. In the US he was part of an intake of 30. In the UK he might have been the only funded econ PhD in his year.
Almost all his peers in the US came from outside the US, and the Americans they had tended to leave early for well paid consultancy and finance sector jobs. Brits were a bit of a rarity, though some others arrived via British Universities. In postgrad economics and academia Italians seem to be everywhere. It may be because their path through from Bucconi, a private University, is more straight forward. In the UK students, unless they are truly exceptional, have to have funded a Masters in order to be able to launch successful PhD applications. (DS took his in EME - Econometrics and Mathematical Economics at the LSE, where home student fees are now £35,472 for 10 months before living costs. Oxford charges less per year but you have college fees and it is a two year course.)
The general rule is to ensure that you learn the maths you will need for the next stage, during the stage before. If you are aiming for a quantitate area of economics, either in the private sector or public sector/academia you are best off looking at the more quantitative undergraduate degrees (Cambridge, Warwick, LSE and UCL). LSE's EME Masters attracts a very international cohort, including Europeans, and both North and South Americans, as it is a way, for say someone who studied at a US Liberal Arts college, to bolster their technical skills before making PhD applications. DS was the only Brit of the 40 in his intake. (Americans at larger better known institutions make up the gap by taking courses from the taught element of the PhD during their UG years.)
Economic PhDs are lucky in that there is a good range of potential employers both in the private and public sectors. Unfortunately for DS, this year's job market was tricky for macro-economists as the US Federal Reserve, who normally soak up a large number of the available cohort, had very few vacancies, which meant that academic jobs elsewhere became unusually competitive. The private sector tends to recruit later so then becomes the fall back. The job market is a sort of UCAS on steroids, with DS applying to almost 250 jobs world wide via a single application. Being a Brit does not help in that British Universities will hire whichever applicant they consider the best, regardless of nationality, whereas Universities in other countries will often favour their own nationals. (I have also heard that those with a six year US PhD are at an advantage over those who have only had three years PhD funding in the UK, but I may be wrong.) There is also language. One reason to study for a PhD in the US is to cement your professional English, enabling you to apply for departments that teach in English. Many of DS' peers, if they were not able to land a job in the US/Canada/UK/Australia were quickly snapped up in their home countries. Much as DS tried to big-up his A* in GCSE German, he was not really in the running outside the Anglophone world. That said, he was offered a couple of surprise flyouts to Asia for departments where though they officially taught in English, not having the language would have been a huge barrier. (He assumes that the departments were wanting a European, especially one with mother tongue English, to bolster their international credentials.)
One oddity about UK academia which the academics on this thread may understand better seems to be that after you land a job, the clock apparently starts ticking and you need to deliver a certain amount of research work within three years in order to gain tenure. And that this is particularly difficult in economics where research, and publication can take a while, especially if you are having to balance it with quite a lot of teaching. On the other hand would be academics going through the UK educational system with double maths A levels and a specialised three year UG degree, exit the system earlier so have more time to add to their experience and CV. One reason for the Americans dropping out mid way through the PhD was that they were older and getting to the point where they wanted to settle down and start earning.
It all worked out fine for DS, and he is looking forward to September. 😀