Modding an Income Modifier Penalty for the player (instead of bonuses for the A.I.)?

[Jet Jaguar]

Is there a way to mod in an income modifier penalty for the player? For example, a -15% modifier to all of the sources of a player's income (taxes, trade and protectorate income)? If this is not possible now, do you think it might be later?

The reason I'm interested in this is because of frustration with the A.I. bonuses of "hard" and "very hard" difficulty levels. Giving the A.I. nations economic bonuses ruins economic strategies that should be used against the A.I. (like blockades and raiding trade routes); with the economic bonuses the A.I. recieves on H & VH, blockades and such often don't make a difference (or at least not their intended difference).

I also think that players start making too much money too early in the campaign. If you could give the player an income modifier penalty, then you wouldn't need to give the A.I. the bonuses of "hard" or "very hard", to make the campaign challenging. Also: for A.I. nations vs. A.I. nations situations, the lack of any A.I. bonuses would probably be a good thing; since they're intended to help the A.I. against the player, not other A.I. nations).

Is it possible to do this? Is there something I'm missing that would make this option a bad idea? Thanks in advance