Taxpayers exert significant effort (about $140B in 2001) to ensure that they’re paying no more than the minimum necessary to comply with myriad federal tax regulations. The Internal Revenue Service also exerts significant effort ($11.1B in 2008) ensuring that taxpayers contribute no less than the minimum proscribed by law.
The efforts of both parties in this minimax exercise could be spent elsewhere. Taxpayers might convert their effort into starting a small business (thus invigorating the economy), putting sweat equity into their house (thus improving their net worth), or just spending a bit more time with friends and relatives in back yard barbeques (thus improving their quality of life). Corporations might gamble on a new product line (thus invigorating the economy) or increase their dividends (thus improving returns for their investors). The federal government might use a reduction in their compliance costs to reduce the federal budget deficit.