This is very dependent on 1 - how you tech vs the AIs 2 - what goals you have 3 - what cities you have 1) if you're hanging behind in techs (like playing deity), lightbulbing opens up trade options, to help you catch up. In this situation, it's almost a must. 2) if you go for cultural, academies give you 4 cpt. But lightbulbing philo gives you a religion (and a holy city is 5 cpt ). If you go for space, you need to think long term. academies are often better. If you want to beeline to something, lightbulbing is often better (every turn counts). If you're building space parts, remember that settled scientists give also 1 hammer. 1 hammer isn't much but it's better than researching a future tech! 3) If you have only poor beaker cities, it's no use to build an academy. Settling a scientist can have more impact in the long run then.