I read this the same way as Max. The issue of cost to solve (eg) all cases of malaria is really tractability, not scale. Scale is how many people would be helped (and to what degree) by doing so. Divide the latter by the former, and you have a sensible-looking cost-benefit analysis, (that is sensitive to the ‘size and intensity of the problem’, ie the former).
I do think there are scale-related issues with drawing lines between ‘problems’, though—if a marginal contribution to malaria nets now achieves twice as much good as the same marginal contribution would in 5 years, are combatting malaria now and combatting malaria in five years ‘different problems’, or do you just try to average out the cost-benefit ratio between somewhat arbitrary points (eg now and when the last case of malaria is prevented/cured). But I also think the models Max and Owen have written about on the CEA blog do a decent job of dealing with this kind of question.
I read this the same way as Max. The issue of cost to solve (eg) all cases of malaria is really tractability, not scale. Scale is how many people would be helped (and to what degree) by doing so. Divide the latter by the former, and you have a sensible-looking cost-benefit analysis, (that is sensitive to the ‘size and intensity of the problem’, ie the former).
I do think there are scale-related issues with drawing lines between ‘problems’, though—if a marginal contribution to malaria nets now achieves twice as much good as the same marginal contribution would in 5 years, are combatting malaria now and combatting malaria in five years ‘different problems’, or do you just try to average out the cost-benefit ratio between somewhat arbitrary points (eg now and when the last case of malaria is prevented/cured). But I also think the models Max and Owen have written about on the CEA blog do a decent job of dealing with this kind of question.