The benefit is doubled in the second case, but the investment is much larger (obviously), so RoI is not doubled. In fact, the investment is more than doubled (you have to pay for two transplants instead of one, as well as killing someone), so the RoI plummets.
What IainM said. RoI is the ratio return/investment. The return is doubled, the investment is (substantially) more than doubled, thus the ratio decreases.
Why not? The investment here being the death of the donor.
The benefit is doubled in the second case, but the investment is much larger (obviously), so RoI is not doubled. In fact, the investment is more than doubled (you have to pay for two transplants instead of one, as well as killing someone), so the RoI plummets.
Thanks, it’s clear to me now. It seems obvious but I didn’t understand it correctly the first time around.
What IainM said. RoI is the ratio return/investment. The return is doubled, the investment is (substantially) more than doubled, thus the ratio decreases.