Capacity for Welfare across Species

Is my dog, with his joyful and carefree life, better off than I am? Do hens in battery cages have worse lives than cows at pasture? Will my money improve welfare more if I spend it on helping people or if I benefit chickens? How can we assess the harm of climate change for both humans and non-humans? If we want to systematically compare welfare across species, we first need to explore whether welf...