Its not from Toby Ord, it is from Nick Beckstead's Thesis.[1]
The idea is introduced as an couple sentence thought experiment in a 200pg thesis (emphasis mine):
>To take another example, saving lives in poor countries may have significantly smaller ripple effects than saving and improving lives in rich countries. Why? Richer countries have substantially more innovation, and their workers are much more economically productive. By ordinary standards, at least by ordinary enlightened humanitarian standards, saving and improving lives in rich countries is about equally as important as saving and improving lives in poor countries, provided lives are improved by roughly comparable amounts. But it now seems more plausible to me that saving a life in a rich country is substantially more important than saving a life in a poor country, other things being equal.
Context is important, specifically the abstract assumptions of fixed cost for each life, and fixed innovative capacity.
You could easily turn the premise around with the opposite conclusion. Improving the innovative capacity in poor countries is more important than saving lives in rich countries, provided you foster more innovation innovation in the poor country than is lost in the rich one.
It looks like an interesting read, covering many topics discussed in this thread.
Chapters include:
Should "Extra" People Count for Less?
Does Future Flourishing Have Diminishing Marginal Value?
A Paradox for Tiny Probabilities of Enormous Values
Infinite Value, Long Shots, and the Far Future
https://scholar.google.com/scholar?hl=en&as_sdt=0%2C5&q=ON+T...