Are you sure about that? In the dev diaries, I think it was .4% production bonus per point of stability above 50, 1% production malus per point of stability below 50. It could have changed since then, but a 50% production bonus at 100 stability seems high.At 50% its 0% penalty/bonus. Every percentage over gives that as a bonus. Eg 67% stability gives a 17% bonus. 30% stability gives a -20% penalty