Negative income tax notion has long been popular in some circles, its implementation has never been politically feasible. This is partly because of the very complex and entrenched nature of most countries' current tax laws: they would have to be rewritten under any NIT system. However, some countries have seen the introduction of refundable (or non-wastable) tax credits which can be paid even when there is no tax liability to be offset, such as the Earned Income Tax Credit in the United States and working tax credit in the UK. In 1971, President Richard Nixon proposed a negative income tax as the centerpiece
Hall income tax and 1960, the court rejected proposals for a general personal income tax. However, in 1981, 1991, and 1999, three different Tennessee Attorneys General issued opinions that a general income tax would not violate the state constitution. In December 2004, a commission established to study the state's tax structure said the Hall income tax was regressive, anti-competitive, and "unfairly selective." However, the Institute on Taxation and Economic Policy (ITEP) said the Hall Tax is actually the only major progressive tax levied in Tennessee—amounting to 0.4 percent of income for high-income taxpayers compared to 0.0–0.1 percent for less affluent Tennesseans. The Tennessee