The economist's apprentice, Miss Emily Anne has an interesting take on wildlife preservationism:

I once read an interview with someone trying to save the tigers. This person lamented the fact that the increasing human population in India was encroaching on tiger habitats. Let's think, if the human population in India had been curbed, the increase in tiger lives would be measured in thousands, while the decrease in human lives would be measured in millions. This struck me as a bizarre tradeoff to wish for. Of course, amongst environmentalists it is a fairly common attitude. Many ordinary folks implicitly think like this, even though most would never admit to preferring one tiger to a thousand people.

This sure does sound like a perverse tradeoff, but don't many of us trade away the lives of the unborn (or more accurately, the unconceived) in favor of goals much less valuable than human lives? Consider the couple that postpones parenthood for a decade so that they can further advance their careers. By virtue of this decision, they have one child instead of three. Three children would have been nice, they agreed, but not at the cost of slowing down their professional advancement.

Is this as unconscionable as the decision to sacrifice two lives for the sake of career advancement? Does it even come close? The fact is that many of us deeply discount potential lives, while distinguishing from actual lives.