I think two things would help clarify the thought experiment:
The cost-effectiveness (units/​$ spent) of each project
A visualization showing the projects as rectangles on a graph. The width of each rectangle is its cost, the height is its cost-effectiveness, and the area is the total amount of good done. We are trying to maximize the area under the curve.
That’s a really good idea, but I don’t think I should prioritize doing that. If you or someone else wanted to supply the relevant images though, I’d be happy to include them.
I think two things would help clarify the thought experiment:
The cost-effectiveness (units/​$ spent) of each project
A visualization showing the projects as rectangles on a graph. The width of each rectangle is its cost, the height is its cost-effectiveness, and the area is the total amount of good done. We are trying to maximize the area under the curve.
There’s another criterion also: the cost-effectiveness has to be over the bar. You could have, e.g. a dashed or coloured line for the bar.
That’s a really good idea, but I don’t think I should prioritize doing that. If you or someone else wanted to supply the relevant images though, I’d be happy to include them.