Hunger strikes seem pointless to a game theorist.  You threaten to starve yourself.  I laugh and wait around until you give up and start eating again.  So why are they so common?  One answer might be that they are not common at all and its for that reason that the few hunger strikes that occur get so much media attention.  But I think they are more common than my caracicture would allow.  For example, there are two big hunger strikes in the news right now. Roxana Sebari, the American journalist imprisoned in Iran was on a hunger strike to draw attention to her captivity.  Mia Farrow, the American actress, was on a hunger strike to draw attention to the crisis in Darfur.

Both were called off in the last few days.  Do hunger strikes every achieve anything?

I can see one way that a hunger strike can be effective for a prisoner held in a foriegn country.  The key idea is that the hunger striker may reach a point where she loses the will/ability to feed herself and then the responsibility shifts entirely on the captors to keep the victim alive.  This may require moving the prisoner to a hospital or some other emergency action which will draw the attention of the international community and potentially bring pressure to allow medical attention from doctors in the prisoner’s home country.

And looking forward to this possibility, the captors may make concessions early to a hunger-striker as now both parties would benefit from preventing the strike from reaching that stage.

Update: Roxana Sebari will be freed today.  I wonder if the hunger strike played any role.  She abandoned it a few days ago and this turn of events today appears to be a total surprise.