I have been speculating how the tax game will change on 1/1/11 - just 8 short months from now. The political climate has created uncertainty in the most important area of investing and economic commerce - taxes. I think it is totally inaccurate when they say - don't base your investment decisions on taxes. When the tax system can swing your after tax returns by 5% - 20% (e.g. Capital Gains increasing 5% to 20% and Dividends at a marginal rate of 36.9% vs 15%), it pays to take notice ahead of the rules change.
So for me - taxes do change behavior. Like business the incentives (positive or negative) need to be carefully thought out or you will create the wrong behavior (and end result). And it becomes worse when you attempt to model an incentive across the entire social demographic population of the U.S.A.
For me - I just enjoy reading the rules of a game and try to understand how people will play it to "win". Winning becomes subjective when the rules change ---- and that is a taxing behavior.