Here’s a thought experiment that recently occurred to me that I’d like to run by you, dear EconLog readers. I think the intuitive reactions one might have to this thought experiment might do a lot to clarify how one conceives of justice. 

Suppose you live in a world where there is a military draft. In addition, let’s stipulate that a military draft is unjust. (If you’re in favor of a draft and find yourself resisting the thought experiment on those grounds, just substitute the draft for some other policy you would consider unjust.) However, not every citizen is eligible for the draft. Only half the population can be drafted. Let’s say the basis for who is eligible is something completely arbitrary – those who were born on even numbered days are eligible to be drafted, while those who are born on odd numbered days are exempt from the draft. 

Let’s say that ending the draft is outside the Overton window – there is no realistic chance this policy can be revoked. However, you are in the unique position of being able to modify the draft with some kind of executive order. You can’t repeal it, but you can make it so those born on odd days become eligible for the draft. Assume nothing else would change if you did so – so for example, if you expand the draft, assume that twice as many citizens will actually get drafted, so nobody with an even numbered birthday sees their chances of being drafted lowered as a result. 

So here’s the question – what is the right thing to do? 

Should the draft be expanded, on the grounds that those born on even days have been treated unfairly by being subject to an unjust policy that other citizens don’t face? That is, should you pull the policy lever that increases the number of people who face injustice, in order to equalize the distribution of injustice? 

Or should you decline to expand the draft, on the grounds that the policy is unjust and if injustice can’t be repealed, as few people as possible ought to be subject to it? That is, should you allow an unjust policy to apply unequally to citizens, in order to minimize the number of people who are subjected to injustice? 

What do you think?