In the United States, the most significant income stream for the federal government is the income tax, for the states it is the sales tax and for local governments it is the property tax. However, feel free to discuss any tax, fee, duty, or other charge imposed by government as you see fit. IMO, a system of tax or taxes works best when it remains entirely true to its original purpose: developing revenues for government operations. The further afield it wanders from that purpose, the less effective it becomes. As a mechanism for forcing social change, the tax system is the very least efficient tool in the government toolbox. So here are some stupid tax provisions I would repeal: 1) The marriage discount. If I and my single neighbor each make $50,000 and we pay tax at a 10% rate (this is all hypothetical), we will pay $5,000 apiece for a total of $10,000. If we marry and file jointly, we'll receive a marriage discount and the first $25,000 of one of our incomes will be sheltered, so our total tax burden is reduced to $7,500. But we are no cheaper to defend, we produce no less garbage that needs collecting, and we need no fewer other government services. The marriage discount exists in our tax law only because of changing social mores in the US concerning married women working outside the home and it has always been irrational as a matter of tax policy. If the government needs only $17,500 to operate, then all adults should be given a share of the tax break; single people should not be underwriting some government costs for married people. 2) Encouraging home ownership. Not merely content to offer a tax discount on the interest paid on both a first and second mortgage on BOTH a first and second home, or a maximum of FOUR mortgages, the US now also awards enormous tax credits to purchasers of residential real property. Home ownership may or may not help stabilize a community but it does not need government intervention to achieve that result -- most folks desire a home of their own without having to be bribed into buying one. Those that are bribed into it may actually be detracting from the stabilization of their communities and in any event, renters should not have to underwrite the cost of home ownership for their neighbors. 3) Encouraging charity. The tax discounts available for gifts to all sorts of charities are so deep, most for-profit corporations have gifting programs. Since corporations are not human, they cannot have "generosity", so this is all done in response to tax discounts. But if the gifting is valuable because of the needs met by charity, then either the gifts should be made without any need for a tax discount or the needs should be elevated to ones met by government. In this vein, tax immunity for charities also seems irrational to me. Why should my Jewish neighbors help underwrite the costs of the local Catholic parochial school? Why should anyone's tax bill go up so as to allow some other private person to "give more"? 4) Discouraging bad habits. When the main purpose of a sin tax is to punish smoking, etc. it is demonstrably ineffective. Because these taxes are not tied to income, they fall much more heavily on the poor than anyone else. I fail to see why my poorest neighbors must suffer disproportionately because I want everyone to stop smoking. Why not merely criminalize smoking? 5) Encouraging certain investments, stimulating the economy, etc. There is a limited value to tinkering with a nation's economy by altering its tax code -- but this will never begin to compete with the effect that can be had by tinkering with its banking system. When we elevate certain investments, e.g., tax rebates for buying energy star appliances or accelerated depreciation for certain asset purchases, what we are trying to do is alter the buying habits of consumers and businesses. Those who do not buy underwrite these acquisition costs for those who do, and the motive -- tax savings -- is not grounded in economic reality. Better to force feed lower interest rates, etc. so that people and businesses buy what they really want and need. Okay, that's a few examples. The bottom line for me is that taxes should be imposed as fairly and simply as possible and ONLY to develop funds to operate government -- not to advance social policies, etc. To do so is inefficient, wasteful and unfair.