The justification behind tax cuts as stimulus is derived from the laissez faire argument and the Laffer curve. While the Laffer curve was made popular by Arthur Laffer on the Reagan administration Economic Policy Advisory Board, it was first described by 14th century Muslim intellectual Ibn Khaldoun. The idea of tax cuts as stimulus was also proposed by John Maynard Keynes though its current proponents appear to be unwilling to associate themselves with Keynesians.
The laissez faire argument states that any transfer of wealth from the state to the people is positive for economic growth since government is always detrimental to the economy. This is a philosophical belief that does not take into account the current state of the world and the limits of short-term change. In the short and medium term, the size of government will not be changed substantially due to the checks and balances that exist in government. Unless there is a national consensus on what must be done, the conflict in competing political interests will prevent large changes from occurring quickly. As this pertains to tax policy and the size of government, unless proponents of smaller government can match tax cuts with spending cuts, government debt will increase creating a larger tax burden on the future economy.
Proponents of tax cuts counter that the Laffer curve proves that tax cuts will not produce deficits because the economic growth produced by the tax cuts will increase total tax revenues. In order for this tax elasticity effect to occur, the current tax rate must be above the rate at which taxes are a disincentive to productivity. Since there is little empirical evidence to support an objective tipping point, the effectiveness of the Laffer curve is dependent on the subjective assessment of whether current taxes are too high. As tax policy is linked to philosophical arguments on the proper size of government, those who believe in smaller government will likely use the Laffer curve to justify lowering taxes without consequence relative to any given rate.