economics because you said you're good at logical thinking. also, it scales better than SDD
I'm biased, lol
Pros: Eco scales well, logical thinking, you get a better idea of how the economy operates, more useful (to me anyway), essay writing improves your English (I do Eco, Ancient and did History Extension - they greatly improved by essay writing in English), it doesn't make me feel like I live under a cardboard box anymore, it's easy to score marks - memorise, and bullshit but it has to be logical nonsense
Cons: I have a terrible teacher, can get a tad bit boring sometimes, you need a good idea of what's going around in the world, opportunity cost of being able to do Physics or Biology