I've thought that the baby boom savings cycle explained most of it, but neat to see some numbers contesting that. But this paper seems to assume that US asset

I've thought that the baby boom savings cycle explained most of it, but neat to see some numbers contesting that. But this paper seems to assume that US asset prices are determined entirely by domestic demand which seems wild in a world awash with sovereign wealth funds, pension plans, diversified savers, and emerging market wealth seeking a safe haven. I see some work attributing pensions, etc. to demographic deciles, but ctrl-F "foreign" comes up 0. Does anyone know of any estimates of what fraction of net inflow into US financial assets are domestic vs foreign?