In Civilization 5, cities will occasionally demand a luxury resource your empire does not have, such as Wine. If you connect this luxury resource to your empire, the city will enter into a We Love the King Day, which gives a bonus to population growth for, not a single day, but rather 20 turns or so.
Do I lose the population growth bonus if I lose access to Wine before the 20 turns is up?
Maybe they only needed the Wine for a single day to experience growth for the next 9 months 20 turns?
