People being convicted of violating unjust laws is a much, much larger problem than people being improperly acquitted. Both because one improper conviction is worse than one improper acquittal, and because I don't actually think improper acquittals really happen much. Opposing jury nullification seems to me like a status move to maintain the power of the lawyers, at the expense of justice.
So if you're on the jury for a case prosecuted under an unjust law, then yes, you do have a moral duty to acquit. Whether you should announce that it's a jury nullification, or lie about how strong the evidence looks to you so others don't get the same idea, is less clear. I lean towards the former.
Yes, a conviction for an unjust law is bad -- that's not in dispute. The problem is whether you are appropriately fighting this injustice by nullifying, if you reason by TDT, a decision theory that ranks very well on numerous desiderata that account for these intuitions. Appealing to specific moral duty doesn't resolve the problem, for the same reason that appealing to greed doesn't justify two-boxing on Newcomb's problem.
For my part, I do have a big problem with drug laws (despite not planning to use them). And before thinking about this as a rationali...
I've been sort of banging my head on this issue (I have jury duty next week (first time)).
The obvious possibility is what if I get put on a drug use case? The obvious injustices of the anti-drug laws are well known, and I know of the concept of nullification, but I'm bouncing back and forth as to its validity.
Some of my thoughts on this:
Thought 1: Just decide if they did it or didn't do it.
Thought 2: But can I ethically bring myself to declare guilty (and thus result in potential serious punishment) someone that really didn't actually do anything wrong? ie, to support a seriously unjust law?
Thought 3: (and here's where TDT style issues come in) On the other hand, the algorithm "if jury member, don't convict if I don't like a particular law" seems to be in general a potentially really really bad algorithm. (ie, one obvious failure mode for that algorithm would be homophobic juries that refuse to convict on hate crimes against gays)
Thought 4: Generally, those sorts of people tend to not be serious rationalists. Reasoning as if I can expect correlations among our decision algorithms seems questionable.
Thought 5: Really? Really? If I wanted to start making excuses like that, I could probably whenever I feel like construct a reference class for which I am the sole member. Thought 4 style reasoning seems itself to potentially be shaky.
So, basically I'm smart enough to have the above sequence of thoughts, but not smart enough to actually resolve it. What is a rationalist to do? (In other words, any help with untangling my thoughts on this so that I can figure out if I should go by the rule of "nullify if appropriate" or "nullification is bad, period, even if the law in question is hateful" would be greatly appreciated.)