For another thing, tax expenditures benefit those at the top of the economic ladder more than those at the bottom. Furthermore, many deductions take the form of reductions in taxable income. Given the progressivity of our tax code, this translates into a higher percentage rate of subsidy to those who incur higher marginal rates. Of course, when tax exemptions do take the form of tax credits that are irrespective of income, they can become a clever way to follow one policy while claiming to follow another. This allows even those who have no tax liability whatsoever to get a 'tax cut,' or what others might call welfare.
Tax expenditures are considerably less accountable than government spending.
When they use conventional spending techniques, legislators must weigh their wish lists with current economic conditions and budgetary constraints. But as the alt-fuel fiasco demonstrates, tax expenditures pay no attention to such conditions. But not all the costs of tax expenditures are so obvious. As the code has swelled, so too have the ranks of certified accountants. Now entire armies of intelligent, hard working individuals do nothing but fill holes that the government has dug.