Playing a run through as Japan, and have Australia as my colony. The AI is happily expanding my colony but I noticed that they are in constant debt. Like 300-400 ducats, not just a small amount. I am able to pay it off for them, but why would they be in debt? No other AI country is attacking me, probably because I've got 700 development and am pretty strong. So it's not a war debt. They are expanding, but only by a province or two at a time. I can't work out why.