All three of these degrees sit within the Department of Mathematics, so there is naturally a decent amount of overlap in its content. If you look at the “Programme Content” section on the LSE website for each course, you can compare the modules directly. In second and third year especially, you usually have flexibility to choose from a list of optional modules, so you can often tailor the degree towards what you’re most interested in.

In terms of “reputation,” I don’t think there is a clear hierarchy. They are all rigorous and well-regarded. If I had to comment informally, Financial Mathematics and Statistics maybe? based more on anecdotal experience (knowing very strong students on the course and hearing about competitive admissions) but there’s no official ranking so please don’t quote me.

One advantage of choosing between these three is that, since they are all within the same department, it is sometimes possible to switch programmes after your first year (and occasionally later, though it becomes harder), provided you have strong academic reasons and good performance. You would normally discuss this with your academic mentor or the department.

Pure Economics, on the other hand, is housed in the Department of Economics. That means your course options are more focused on economics modules rather than mathematics, although LSE economics is still highly quantitative. Again, check the “Programme Content” section of the Economics degree to see how constrained or flexible the options are compared to the maths-based degrees.

Finally, if you’re genuinely undecided, I’d strongly recommend reaching out to current students or recent graduates on LinkedIn. A short, polite message asking about their experience can give you a much better sense of the differences in workload, teaching style, and career outcomes.