Beckstead is credited as one of the founders of longtermism because of his 2013 PhD dissertation titled "On the Overwhelming Importance of Shaping the Far Future," which longtermist Toby Ord describes as "one of the best texts on existential risk." Beckstead made the case therein that what matters more than anything else in the present is how our actions will influence the future in the coming "millions, billions, and trillions of years." How do we manage this? One way is to make sure that no existential risks occur that could foreclose our "vast and glorious" future among the heavens, with trillions of simulated people living in virtual realities. Another is to figure out ways of altering the trajectory of civilization's development: Even small changes could have ripple effects that, over millions, billions and trillions of years, add up to something significant.
One implication of Beckstead's view is that, to quote him, since "saving lives in poor countries may have significantly smaller ripple effects than saving and improving lives in rich countries, … 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."
Why would that be so, exactly? Because "richer countries have substantially more innovation, and their workers are much more economically productive."