Rule by the dead.
A system of government wherein a hive mind, made up of the collective consciousnesses of the deceased, will use the collected experience of all the previous inhabitants of this system to, theoretically find the best solution to all problems.
Pro's: Better than AI rule because of the human element, better than human rule because of robotic rationality and the fact the dead don't really have a horse in the race anymore.
Con's: As life expectancy increases so government will becoming increasingly conservative, gerrymandering via mass suicide, the usual problems of ennui dropping safety concerns associated with any sort of i