Question Does the great size of the population give me an out, since my contribution, say one in 150,000,000, is neither here nor there, when it comes to,say, voting, recycling garbage, paying taxes? Of course, if "everybody did it", it would be a problem. But everybody, in fact, isn't doing it, so there is no actual problem. My failure to co-operate has a minimal impact. And, my keeping quiet about my non-co-operation further minimizes the minimal impact.

Accepted:
June 5, 2008

Comments

Suppose that by mailing in a postcard you could get a 1 in 10 chance to direct $10,000 to a good cause: an orphenage, say, or a promising development project in Africa. Would you mail the postcard? I suppose you would. You would say that a 1 in 10 chance of $10,000 is worth about as much as $1000 for certain. So this is very much worth a postage stamp.

Now consider the same question in regard to a 1 in 20 chance of being able to direct $20,000 to a good cause. The probability that it will work out is smaller, to be sure, but the good it would do is correspondingly larger. So again it would seem that you have very strong reason to mail that postcard.

Voting in the US election comes rather later in this chain. Your chance of affecting the result is very small, but the payoff is correspondingly larger. The difference between a good and a bad US President is huge for a generation of human beings and possibly future ones as well. So don't be fooled by the small probability; it isn't zero. And do not think only how the election is going to affect yourself but also think of the billions who will be affected as well -- many of them more than yourself.

Now to the garbage, taxes, pollution cases. Assume first that the harm done is proportional to the total so that, say, every mile you drive shortens human lives by a total of 10 seconds. Since your car's pollution gets spread worldwide, these 10 seconds get distributed over 6.9 billion people, so you're really doing no harm at all. Right?

Well, over your life you drive about 1 million miles. This shortens human lives by about four months. Still, you'll say, this is insignificant, because every human being on earth loses only 1/690 of a second of life.

Suppose there are about 2.3 billion polluters like yourself. Together, you guys are shortening each human life by 3.33 million seconds or 39 days.

When you think of each polluter as taking 1/690 of a second of life away from every human being, then it may look insignificant. But if you group the losses differently, it looks worse: each is then taking 39 days from three persons.

Assume now that the harm is lumpy. A certain amount of pollution does no harm to anyone, but when the level gets high enough there is the chance of catastrophic climate change. This case is more like the voting case. Instead of certainly taking four months of life from human beings, your driving career now has a 1 in 1000 chance of taking 4000 months, or a 1 in 1 million chance of taking 4 million months. Again, the expected disvalue of your driving is four months of lost life. Hardly something you can ignore.

In conclusion, the great size of the population is really irrelevant. Even if one holds fixed what the others do, as you propose, the expected impact of what you do is not minimal at all. For much more on all this, see Derek Parfit's book Reasons and Persons.