For example, let's say in society A, rich people pay less in tax, can invest more in the stock market, and consequently certain businesses do better and the shop fronts are more attractive. There is a downside: homeless people can be seen panhandling in every plaza.
In society B, the rich pay more in tax, there's a bit less investment in the stock market, some businesses do worse, and the shop fronts look less attractive. However, there are no homeless people. They all have homes and can afford food, and some have gotten steady jobs.
If someone claimed that the nicer shop fronts and other perks in society A were appealing but were effectively paid for by the poor, who became homeless, the riposte would no doubt be that the poor/homeless people may be unfortunate but aren't really earning or paying for much either way. It is the rich who are paying to support the poor in society B.
But imagine if the negative side effect of society A's perks, instead of homelessness, were the loss of many wild places and the extinction of many species. Could the same riposte be made?
We'd see the suffering and death of wild creatures as a valid form of payment: they were paying for something, a consequence of more attractive store fronts and a few businesses doing better. This might give us more pause.
It should give us as much pause when those suffering are human.
