Sid Meier's Civilization V

Sid Meier's Civilization V

Economics
How does the mod work, exactly?
I know what GDP is but I have no idea how I can increase it. I'm in almost constant recession and the mod costs me about twice as much as it makes me and I have no clue how increase my income or mitigate my expenses, I can only watch as my economy is dragged through the dumps. My gold and culture are extremely low which makes the game very hard to play. If someone could explain to how to use this mod I'd be very grateful.