[desertedisland]

Well it's an interesting question and the answer is not ambiguous as far as I can tell. The US share of global R&D spending on pharmaceuticals is approaching 60%: https://www.abpi.org.uk/facts-and-figures/science-and-innova...

To answer your question I think there's little doubt that dramatically cutting health (and pharmaceutical) costs per person in the US (i.e. with a single payer model) would dramatically impact global R&D spending on pharmaceuticals.

But are you saying that the average American citizen is ok paying ridiculous health care costs (with only a limited number of citizens having coverage) because their payments are subsidising global health R&D? I really, really doubt that. Also this idea is clearly socialist which is one of the main arguments against universal health coverage in the US.