"If Niantic would incentivize being on the minority team (like bonuses for battling), the team ratio would even out."

#PokemonGO: Gym turnover is essential for the gym system, whether people like it or not. This new way to switch teams will make Mystic ever increase in numbers which will be unhealthy for the game in the long run. Gym stagnation would be a real issue, gym battling would be demotivating and some teams in some areas may never see the light of day.​If Niantic were to make battling more rewarding, people would find that they'd want to be on the minority team. If everyone wants to be on a minority team, the teams will eventually balance out. Also they need to get rid of "team contribution" in raids and focus much more on individual contribution, (although gym team bonus can stay). via /r/TheSilphRoad http://bit.ly/2GxkXzU