Is a unit of suffering less complex than a unit of happiness, and, therefore, more likely to occur in the universe, all else equal? I realize this is an insanely difficult question, but would be interested in current opinions and any related evidence.
A similar question is whether happiness and suffering are equally energy-efficient.
Maybe I misunderstand something, but why would less complexity imply higher frequency when those being capable of experiencing either will generally strive for happiness?
If the majority of minds with moral weight are the result of an intelligent mind's decision, then the link between complexity and frequency may be weak. Pain is a strong motivator for some things, even if it's bad at motivating creativity, so perhaps there would still be an incentive to create more pain. This is extremely speculative though.
The bigger worry would be that forces like Moloch and evolution may favor pain. Wild animals appear to have much more pain in their lives than pleasure. Even if the carrot was a more effective motivator than the stick for something, if pain was simpler and more robust evolution would still favor it.
This would be especially important for things like Boltzmann brains. To me it seems unlikely to me that things like trees or insects can suffer, but if they can we'd have a very hard time relating to minds so different from our own. With so little evidence, the choice of a good prior is crucial, so it would be useful to have a prior for the predominance of suffering over happiness.