几十年来，保守派坚持认为经济繁荣的关键在于减轻赋税。如果按共和党提名候选人Donald Trump提出的税收计划，仅占0.1%的顶层收入人群每人每年在税费上的支出将减少约130万美元，这一计划与保守派的观点不谋而合。

On the other hand, Democrats such as front-runner Hillary Clinton take another approach. Clinton says she'll reform the U.S. tax code so that the wealthiest pay their fair share. The response from Republicans has been predictable: They argue that such a tax plan will lower growth and harm the economy. 

另一方面，民主党内大热的提名候选人Hillary Clinton则有不同的做法。Clinton称她将对美国税码进行改革，让那些顶层收入人群承担其公平份额。共和党人对此的回应不难预见：他们称该税收计划将减缓增长并对经济造成损害。

向富人增税 对经济增长是利是弊

Do the conservative arguments against tax increases have any merit? Or are they, as Democrats claim, a way to serve an ideological goal of smaller government and reward wealthy Republican donors? Let's take a closer look.

保守派反对增税的理由究竟有没有可取之处？亦或者，像民主党人所说的那样，只是为达成小政府的意识形态目标而服务，顺带回报一下富有的共和党捐款人？现在让我们对这些（理由）做更进一步的了解。

Increasing taxes on the wealthy will harm economic growth: This argument is made frequently, along with the claim that increasing growth will lift all boats, but the evidence doesn't support either claim. As Nobel Prize-winning economist Peter Diamond and John Bates Clark medalist Emmanuel Saez have noted, since the 1970s no clear correlation exists between economic growth and top tax-rate cuts across Organization for Economic Cooperation and Development countries. 

对富人增税将损害经济增长：这种说法我们经常能听到，与此说法一起出现的还有经济的持续增长将会让所有人的财富都随之水涨船高，然而现有证据都不支持以上两种说法。诺贝尔经济学奖得主Peter Diamond和约翰·贝茨·克拉克奖得主Emmanuel Saez曾指出，20世纪70年代以来，在经济合作与发展组织（OECD）各成员国内，经济增长与最高税率削减之间并无明显关联。

As for the trickle-down argument, this claim falls apart when you examine what happened to the distribution of income after tax cuts for the wealthy enacted during the Bush administration. Income of those at the top went up substantially, with no corresponding gain for those lower in the income distribution.

至于“涓滴效应”的理论，当你回头审视Bush政府所推行的减税政策对收入分配的影响之后，会发现这一主张根本站不住脚。顶层人士的收入大幅增加，与此同时低收入人群的收入水平却并未出现相应的增长。

If the wealthy aren't willing to move between states in response to tax differences, it seems even more unlikely that would undertake the far more difficult task of moving to another country. 

既然富人们不愿意因税收差异而移居其他州，那么他们也更不会选择承担更多风险而移居国外了。

Increasing taxes on the wealthy won't increase tax revenue: The Laffer curve argument that increasing taxes will cause the wealthy to pursue tax-avoidance strategies or forego profitable opportunities to the extent that tax revenues actually fall has been examined again and again, and the message is clear. Tax avoidance may increase somewhat, but nowhere near enough to cause tax revenues to fall. 

对富人增税不能增加税收收入：拉弗曲线理论问世至今已经历过一次又一次地检验，所传递出的信息十分明确，即富人会通过寻求避税策略或是放弃获利机会的方式来应对增税，这样一来，实际税收收入将会下降。避税行为会有所增加，但不足以导致税收收入下降。

Diamond and Saez have looked at this closely, and they found that the revenue-maximizing top federal marginal income tax rate would be in or near the range of 50 percent to 70 percent (taking into account that individuals face additional taxes from Medicare and state and local taxes).

Diamond和Saez曾对此进行过详细研究，发现当联邦边际所得税率最高值处在或接近50%至70%这一范围内时，才能实现收入的最大化（考虑到个人还会遇到一些额外税种，如医疗险、州税、地方税）。

Less will be donated to private charities: Would tax increases cause the wealthy to reduce their charitable giving? Research on this question suggests it's the other way around. Back in the 1970s, when the top rate of federal income tax was 70 percent, wealthier Americans (those with incomes of over $500,000 in 2007 dollars) gave around twice as much of their money to charity than they did in 2007, when the top rate had fallen to 35 percent.

私人慈善机构的受捐赠数额将会减少：增税是否会导致富人慈善捐款数额的减少？关于此问题的研究所得出的结论恰好与此相反。在20世纪70年代，当时的联邦所得税的最高税率达到了70%，富人们（按2007年美元币值来算他们的收入超过了50万美元）的慈善捐款数额是其2007年捐款额的两倍，而2007年时最高税率已经降至35%。

Why does this happen? When taxes are higher, the benefit of the tax deduction for charitable giving is also higher, so people tend to increase the amount they give. In addition, the wealthy give their biggest donations almost exclusively to universities and colleges, hospitals and medical centers, and arts institutions. They rarely make large gifts to social-service groups,grass-roots organizations or noNPRofit groups that focus on the poor or minorities.

为何会出现这种情况？当税收增高时，相应的慈善捐赠所带来的税收减免优惠也更大，因此人们乐于增加捐款数额。此外，富人们的大部分捐赠基本都流向了高等院校、医疗机构、文艺机构。他们很少会将大笔款项捐赠给关注低收入和少数族裔群体的社会服务组织、基层组织或者非营利组织。

So to the extent that the increased tax revenue is used to support these groups, social welfare could benefit.

因此，在一定程度上，增加税收收入可以更好地扶持这些组织，社会福利将从中受益。

The wealthy deserve what they earn: This argument assumes that they're paid according to their contribution to society. But in a world of monopoly power, regulatory capture and a symmetric power relationships in bargaining over the wage and profit shares of business earnings, the presumption that those at the top of the income distribution earned their income flies out the window.

富人挣来的钱都是他们应得的：这一理论假设富人们是因其对社会的贡献而获得的报酬。但现实却是，在商业收入的报酬和利润分成拉锯战中，充斥着垄断势力、规制俘获和不对称的权利关系，因而顶层收入人群获得的是其应得的报酬这个假设不成立。

If we assume that fairness is defined as keeping what you contribute to the social good (what economists would call the value of their marginal product), and no more than that, such fairness would compel us to take the income the wealthy earn in excess of their contribution to the social good.

如果我们假设，公平的定义是保持对社会的贡献（经济学家称之为“边际产品价值”），除此外没有其他因素，这样的公平将促使我们向富人要回超出他们对社会贡献的那部份收入。

Arguments about the size of government and the taxes needed to support the many things that government does are certainly fair game for politicians. But the argument that tax increases on the wealthy will cause substantial harm to the economy does not withstand a close look at the evidence.

关于政府规模和运作政府所需要的税收收入之类的争论显然是政客们之间的公平博弈。而向富人增税会严重损害经济的这一理论，在我们对这些证据进行仔细分析后，显然是不成立的。