OK I’m really confused—you calculate ~0.001 DALYs (which i guess is ~9 disability-adjusted life-hours) lost per person to eliminating people’s freedom to consume sugary drinks, adjust that down because you’re not eliminating it but just restricting it, make a second adjustment which I don’t understand but which I’ll assume is OK, multiply by the population of the average country to get a total number of DALYs, then:
Fourthly and finally, we divide by overall diabetes mellitus type 2 disease burden, thus creating an estimate −0.001% to be used as a downward adjustment on impact.
But you estimate that taxing sugary drinks won’t eliminate the DMT2 disease burden, but instead reduce it by 0.02%. So shouldn’t this factor instead be 0.001% / 0.02% = 5%?
Let me try to do a rough calculation myself: if you world-wide banned sugary drinks, each person would lose 0.001 DALYs total over the rest of their lives [EDIT: this is wrong, it’s per annum, see this comment for a corrected version of the following calculation].
What’s the disease burden caused by DMT2? Your report says roughly 90 million DALYs, I’m going to assume that’s per year (you probably say this somewhere or it’s probably an obvious convention, but I couldn’t find it easily and don’t know the conventions in this field). The global average age is ~30 and average life expectancy is ~70, so let’s multiply that by 40 remaining years to say 3,600 million DALYs of total DMT2 burden for the present population over the rest of their lives. Banning sugary drinks would reduce that burden by 5%, for a gain of 180 million DALYs. There are ~8 billion people on earth, so that’s 0.02 DALYs per person gained by banning sugary drinks.
So loss of freedom of 0.001 DALYs reduces the benefit of 0.02 DALYs by 0.001 / 0.02 = 5%, agreeing with my guesstimate above (assuming that the ratio is the same for a tax vs an all-out ban, which seems right to first order).