So, in gw3, we have a two "random" events happening in the US at the same time: bird flu outbreak for North America and lack of safety confidence in the US. I see two issues:
1. Demand charts only have 1 event showing as impacting demand (I suspect because there was an assumed business rules that two events in one location would not be active). The demand levels only appear to take into account the impact of one event, but I wouldn't be surprised if both events were actually impacting demand.
2. From a game playability perspective two massive long term events that nerf demand is probably a bit much, and I wouldn't be surprised to see a mass game world exit as the flies drop (much like that challenge game a long while back that cleared the deck with insane fuel prices).