If you don’t think you could convince him to cooperate then you still defect because he will, and if you cooperate 0 people are saved. Cooperating generates either 0 or 2 billion saved, defecting generates either 1 or 3 billion saved. Defect is clearly the better option.
If you were going to play 100 rounds for 10 or 20 million lives each, cooperate by all means. But in a single round PD defect is the winning choice (assuming the payout is all that matters to you; if your utility function cares about the other persons feelings towards you after the choice, cooperate can become the highest utility)
If you don’t think you could convince him to cooperate then you still defect because he will, and if you cooperate 0 people are saved. Cooperating generates either 0 or 2 billion saved, defecting generates either 1 or 3 billion saved. Defect is clearly the better option.
If you were going to play 100 rounds for 10 or 20 million lives each, cooperate by all means. But in a single round PD defect is the winning choice (assuming the payout is all that matters to you; if your utility function cares about the other persons feelings towards you after the choice, cooperate can become the highest utility)