失去移民，美国经济将会怎样

    在这幅图中，各国之间的差距小了很多。实际上，美国甚至不再是第一名。按人均值计算，这些国家的经济增长率分别为：

    • 英国2.0%

    • 美国1.8%

    • 日本1.6%

    • 法国1.2%

    如果不考虑较快的人口增长，美国和同类富裕国家在经济增长方面的差异就会少很多。这让我们看清楚了一些问题，比如当下对美国医疗改革的探讨。英国有社会化医疗，它让政府支出占年度GDP的比重提高到近50%；在这种情况下，英国的人均GDP增长速度还超过了美国，而后者的政府开支在GDP中所占的比例较小。

    所以说，人口增长有利于经济发展。这似乎显而易见——更多的人口意味着更多的经济活动。在美国，人口增长越来越依赖于移民。当然，美国的人口出生率高于其他富裕国家，但这个数字正在下降。美国人口普查局（Census Bureau）估算，移民将是今后30年美国人口增长的主要动力。

    目前人们正在讨论财富和收入差距不断拉大的现象，引发这场讨论的很大一部分数据都由法国经济学家托马斯•皮凯蒂负责整理。皮凯蒂在他即将出版的新书《21世纪的资本》（Capital in the 21st Century）中谈到了这个问题。他指出，在美国历史上，私人财富在很长一段时间里都没有像欧洲那样不平均地高度聚集起来，其中的主要原因就是移民。皮凯蒂写道：

    （移民）是美国对全球再分配做出的巨大贡献：独立战争期间，美国的人口数量几乎不到300万，现在增长到了3亿多，主要得归功于连续不断的移民浪潮。这就是为什么美国还远远不会成为新的老式欧洲……移民像灰浆一样把美国砌成了一个整体；他们具有稳定作用，让越来越大的劳动收入差距在政治和社会层面变得可以忍受……在收入水平处于后一半的美国人中，相当多的人认为收入不均是第二重要的事情，原因仅仅是他们出生在一个不太富裕的国家，而且认为自己的人生轨迹正在上升。

    换句话说，移民不仅促进经济增长，它还防止财富的集中在整个发达世界引发政治不稳定局面。人口增长没有降低有钱人的富裕程度，但它确实削弱了财富的力量。和人口与经济都在增长的国家相比，以及人口和经济都处于滑坡状态的国家，一百万美元的价值要高得多。（财富中文网）

    译者：Charlie

    Here, the competition is much closer. In fact, the U.S. doesn't even win. On a per capita basis, these countries grow at:

    • 2.0% in the U.K.

    • 1.8% in the U.S.

    • 1.6% in Japan

    • and 1.2% in France.

    Take away America's faster population growth, and there's a lot less of a difference between its economic growth compared to its wealthy nation peers. This puts into perspective, for instance, the current debate over health care reform in the U.S. Britain has socialized medicine, a fact that pushes the share of yearly GDP spent by the government close to 50%, yet it has managed to grow its economy faster than the U.S. on a per-capita basis, for which government spending represents a smaller share of GDP.

    So, population growth is good for economic growth. This seems intuitive -- more people means more economic activity. And in the U.S., population growth is increasingly reliant on immigration. Sure, birth rates are higher in the U.S. than in other wealthy countries, but they are on the decline, and the Census bureau estimates that immigration will be the main driver of population growth within 30 years.

    Thomas Piketty, the French economist responsible for compiling much of the data driving today's debate over growing wealth and income inequality, raises this issue in his forthcoming book, Capital in the 21st Century. He points out that immigration is also the primary reason the U.S. has, for much of its history, avoided the large and unequal concentrations of private wealth that developed in Europe. He writes:

    [Immigration] was the great contribution of the United States to global redistribution: the country grew from a population of barely 3 million at the time of the Revolutionary War to more than 300 million, largely thanks to successive waves of immigration. That is why the United States is still a long way from becoming the new Old Europe ... immigration is the mortar that holds the United States together, the stabilizing force that makes increasingly large inequalities of labor income politically and socially bearable ... for a fair proportion of Americans in the in the bottom 50 percent of income, these inequalities are of secondary importance for the very simple reason that they were born in a less wealthy country and see themselves as being on an upward trajectory.

    In other words, not only does immigration boost growth, it also combats the kind of concentration of wealth that has fueled political unrest across the developed world. Population growth doesn't make the rich any poorer, but it does diminish the power of wealth. A million dollars is going to be a much more valuable thing to have in a country in which the population and economy are shrinking than in a country where the population and economy are growing.