The penalties of negative morale seem pretty straightforward; chance of riots that render population units non-productive*; chance of outright revolts if enough people are unhappy relative to available ground troops / militia. Is there anything here that I'm missing?
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* Though I think they still count towards the population thresholds for buildings?
Edit: This quote from this post seems to answer my question:
At least, the implication is that positive effects for high morale aren't currently in-game.Arioch wrote:We also plan to add some positive effects for high morale, which cyborgs will be unable to benefit from.