Macroeconomic theory
Supply-side economics is a macroeconomic theory postulating that economic growth can be most effectively fostered by lowering taxes, decreasing regulation, and allowing free trade. According to supply-side economics theory, consumers will benefit from greater supply of goods and services at lower prices, and employment will increase. Supply-side fiscal policies are designed to increase aggregate supply, as opposed to aggregate demand, thereby expanding output and employment while lowering prices. Such policies are of several general varieties:
A basis of supply-side economics is the Laffer curve, a theoretical relationship between rates of taxation and government revenue. The Laffer curve suggests that when the tax level is too high, lowering tax rates will boost government revenue through higher economic growth, though the level at which rates are deemed "too high" is disputed. A 2012 poll of leading economists found none agreed that reducing the US federal income tax rate would result in higher annual tax revenue within five years. Critics also argue that several large tax cuts in the United States over the last 40 years have not increased revenue.
The term "supply-side economics" was thought for some time to have been coined by the journalist Jude Wanniski in 1975; according to Robert D. Atkinson, the term "supply side" was first used in 1976 by Herbert Stein (a former economic adviser to President Richard Nixon) and only later that year was this term repeated by Jude Wanniski. The term alludes to ideas of the economists Robert Mundell and Arthur Laffer.
Historical origins.
Supply-side economics developed in response to the stagflation of the 1970s. It drew on a range of non-Keynesian economic thought, including the Chicago School and New Classical School. Bruce Bartlett, an advocate of supply-side economics, traced the school of thought's intellectual descent from the philosophers Ibn Khaldun and David Hume, satirist Jonathan Swift, political economist Adam Smith and United States Secretary of the Treasury Alexander Hamilton. In 2007, Bartlett stated:
 ;templatestyles src="Template:Blockquote/styles.css" / ;Today, hardly any economist believes what the Keynesians believed in the 1970s and most accept the basic ideas of supply-side economics – that incentives matter, that high tax rates are bad for growth, and that inflation is fundamentally a monetary phenomenon. Consequently, there is no longer any meaningful difference between supply-side economics and mainstream economics.
Today, supply-side economics has become associated with an obsession for cutting taxes under any and all circumstances. No longer do its advocates in Congress and elsewhere confine themselves to cutting marginal tax rates – the tax on each additional dollar earned – as the original supply-siders did. Rather, they support even the most gimmicky, economically dubious tax cuts with the same intensity. ... today it is common to hear tax cutters claim, implausibly, that "all" tax cuts raise revenue.
Current day advocates of supply-side economic policies claim that lower tax rates produce macroeconomic benefits and emphasize this benefit rather than their traditional ideological Classical liberals opposition to taxation because they opposed government in general. Their traditional claim was that each man had a right to himself and his property and therefore taxation was immoral and of questionable legal grounding. On the other hand, supply-side economists argued that the alleged collective benefit (i.e. increased economic output and efficiency) provided the main impetus for tax cuts. As in classical economics, supply-side economics proposed that production or supply is the key to economic prosperity and that consumption or demand is merely a secondary consequence. Early on, this idea had been summarized in Say's law of markets, which states: "A product is no sooner created, than it, from that instant, affords a market for other products to the full extent of its own value." or, in other words, production (supply) must first occur to enable economic activity or trade.
Supply-side economics rose in popularity among Republican Party politicians from 1977 onwards. Prior to 1977, Republicans were more split on tax reduction, with some worrying that tax cuts would fuel inflation and exacerbate deficits. In 1978, Jude Wanniski published "The Way the World Works" in which he laid out the central thesis of supply-side economics and detailed the failure of high tax rate progressive income tax systems and United States monetary policy under Richard Nixon and Jimmy Carter in the 1970s. Wanniski advocated lower tax rates and a return to some kind of gold standard, similar to the 1944–1971 Bretton Woods System that Nixon abandoned.
Definition and principles.
James D. Gwartney and Richard L. Stroup provide a definition of supply-side economics as the belief that adjustments in marginal tax rates have significant effects on the total supply. Gwartney and Stroup said "that the supply-side argument provided the foundation for the Reagan tax policy, which led to significant reductions in marginal tax rates in the United States during the 1980s".
Barry P. Bosworth has provided another definition by presenting the supply-side economics from two perspectives:
Supply-side vs. previous approaches to economic policy.
Supply-side economics has originated as an alternative to Keynesian economics, which focused macroeconomic policy on management of final demand. Demand-side economics relies on a fixed-price view of the economy, where the demand plays a key role in defining the future supply growth, which also allows for incentive implications of investment.
The Keynesian policy approaches focus on demand management as a major instrument to affect aggregate production and GNP, while Monetarism focuses on management of monetary aggregates and credit. Unlike supply-side economics, demand-side economics is based on the assumption that increases in GNP result from increased spending.
Traditional policy approaches were challenged by the theory of supply-side economics in the Reagan Administration of the 1980s. It claims that fiscal policy may lead to changes in supply as well as in demand. So, when marginal tax rates are high, consumers pursue additional leisure and current consumption instead of pursuing current income and extra income in the future. Therefore, there is a decline in work effort and investment, which in turn causes a decrease of production and GNP, regardless of the total demand levels.
On these assumptions, supply side economists formulate the idea that a cut in marginal tax rates has a positive effect on economic growth.
Role of the marginal tax rates.
The main focus of supply-side economics is promotion of economic growth. In this regard, some studies have suggested to consider two relative prices.
The first one influences decisions of individuals on the distribution of their income between consumption and savings. The cost of individual's decision to assign a unit of income to either consumption or savings is a future value of the unit, which has been given up by choosing either to consume or to save. The unit of income value is defined by the marginal tax rates. Therefore, higher tax rates would decrease the cost of consumption, which would cause a fall in investment and savings. At the same time, lower tax rates would cause the investment and savings levels to rise, while the consumption levels would fall.
The second price influences decisions of individuals on the distribution of their time between work and leisure. The cost of individual's decision to allocate a unit of time either to work or leisure stands for current income, which was given up by choosing either work or leisure. The cost also includes the future income, which was given up for leisure instead of enhancing the professional skills. The value of lost income is defined by the tax rate assigned to the additional income. Therefore, the increase in marginal tax rates leads to a decrease in the price of leisure. However, if the marginal tax rate decline, the cost of leisure increases.
Both the amount of retained and taxed income is determined by the marginal tax rate. That is why, from a supply-side economist's standpoint, marginal tax rates play a significant role in determining the development of the economy. Due to crucial role in determining how much time workers will spend on work and leisure or how much income will be spent on consumption and for savings, supply-side economists insist on decreasing tax rates as they believe it could improve the growth rates of the economy.
Laffer curve.
Laffer curve illustrates a mathematical relationship between tax revenues and tax rates, which was popularized by economist Arthur B. Laffer in 1974. The Laffer Curve posits the existence of a maximum point when tax revenue is maximized at a specific (unknown) tax rate. Many interpret the Laffer Curve as higher tax rates can sometimes decrease the tax base, which will lead to the decrease in tax revenues even if the tax rates are high. Due to the effect exerted by taxes on the taxed income, the adjustment of tax rates may not lead to proportional changes in tax revenues. That is why, some supply-side economists insist decreasing high tax rates can result in an increase of tax revenues.
The Laffer curve embodies a postulate of supply-side economics: that tax rates and tax revenues are distinct, with government tax revenues the same at a 100% tax rate as they are at a 0% tax rate and maximum revenue somewhere in between these two values. Supply-siders argued that in a high tax rate environment lowering tax rates would result in either increased revenues or smaller revenue losses than one would expect relying on only static estimates of the previous tax base.
This led supply-siders to advocate large reductions in marginal income and capital gains tax rates to encourage greater investment, which would produce more supply. Jude Wanniski and many others advocate a zero capital gains rate.
History.
Reaganomics.
In the United States, commentators frequently equate supply-side economics with Reaganomics. The administration of Republican president Ronald Reagan promoted its fiscal policies as being based on supply-side economics. Reagan made supply-side economics a household phrase and promised an across-the-board reduction in income tax rates and an even larger reduction in capital gains tax rates. During Reagan's 1980 presidential campaign, the key economic concern was double digit inflation, which Reagan described as "[t]oo many dollars chasing too few goods", but rather than the usual dose of tight money, recession and layoffs, with their consequent loss of production and wealth, he promised a gradual and painless way to fight inflation by "producing our way out of it".
Switching from earlier monetary policy, Federal Reserve chair Paul Volcker implemented tighter monetary policies including lower money supply growth to break the inflationary psychology and squeeze inflationary expectations out of the economic system. Therefore, supply-side supporters argue that Reaganomics was only partially based on supply-side economics.
Congress under Reagan passed a plan that would slash taxes by $749 billion over five years. Critics claim that the tax cuts increased budget deficits while Reagan supporters credit them with helping the 1980s economic expansion and argued that the budget deficit would have decreased if not for massive increases in military spending. As a result, Jason Hymowitz cited Reagan—along with Jack Kemp—as a great advocate for supply-side economics in politics and repeatedly praised his leadership.
Critics of Reaganomics claim it failed to produce much of the exaggerated gains some supply-siders had promised. Paul Krugman later summarized the situation: "When Ronald Reagan was elected, the supply-siders got a chance to try out their ideas. Unfortunately, they failed." Although he credited supply-side economics for being more successful than monetarism which he claimed "left the economy in ruins", he stated that supply-side economics produced results which fell "so far short of what it promised", describing the supply-side theory as "free lunches".
Clinton years.
Clinton signed the Omnibus Budget Reconciliation Act of 1993 into law, which raised income taxes rates on incomes above $115,000, created additional higher tax brackets for corporate income over $335,000, removed the cap on Medicare taxes, raised fuel taxes and increased the portion of Social Security income subject to tax, among other tax increases. Frankel and Orszag described the "progressive fiscal conservatism" of the 1993 package: "Such progressive fiscal conservatism combines modest attempts at redistribution (the progressive component) and budget discipline (the fiscal conservative component). Thus the 1993 package included significant spending reductions and tax increases. But it concentrated the tax increases on upper-income taxpayers, while substantially expanding the Earned Income Tax Credit, Head Start, and other government programs aimed at lower earners." The tax increases led to greater revenue (relative to a baseline without a tax increase).
The bill was strongly opposed by Republicans, vigorously attacked by John Kasich and Minority Whip Newt Gingrich as destined to cause job losses and lower revenue.
Economist Paul Krugman wrote in 2017 that Clinton's tax increases on