Just as the title says. Finance are relevant to economy. Isn't true we need to understand economy to invest better?
From the FAQ, regarding off-topic questions (emphasis added):
Academic questions about economics or questions about economics that have no bearing on personal finance
In other words, this site is not the correct place for many questions that economics majors or economists would discuss. It basically comes down to whether the topic is relevant to personal finance.
The Economics Stack Exchange is now in public beta. If you're interested in economics Q&A, you are encouraged to visit economics.stackexchange.com. Thank you.
I'm not an expert on the rules here, but I think the reason why economics questions are separate from personal finance is because personal finance has lots of practical considerations that have little to do with the economy.
Questions about tax-advantaged savings accounts, cd laddering, home mortgages, budgeting, etc. are independent of the macroeconomic climate. Our society has an overwhelming number of personal finance options and terminology that you need to have a good understanding of just to be a responsible adult. The rules regarding taxes alone are insanely complicated. Mortgage terms and fees are also complicated. But all of these rules and knowledge have practical value.
If economic theory questions come into scope, then it will be much harder to find the practical Q&A discussions that we have now.