These documents have become less sought after among the ranks of the world's highly skilled migrants.
这些文献越来越少地被世界级排名的高技术移民者翻阅。

The United States has always been known as a nation of immigrants and a top destination for scientists and other highly skilled professionals. That ability to attract the world's most educated and innovative people to its shores has often been credited with powering the US economy.
众所周知，美国是个移民国家，是那些科学家以及其他高技术专业人员移民的首选目的地。美国有着能吸引世界受过高等教育和具有创新意识的人们来到美国的能力，是推动美国经济的动力。
But strikingly, a new study of worldwide migration patterns suggests the US is losing its reputation as a mecca for professionals as its global share of the most highly educated migrants declines. The result raises the question of whether the country can remain competitive in attracting top talent in an increasingly globalized economy.
但是显而易见的是，一个关于全世界范围移民模式的新研究表明美国正失去作为专业人员圣地的声誉，因为受过高等教育移民者份额在减少。研究结果引发疑问：在经济日益全球化的情况下，美国是否还能保持具有吸引顶尖人才的竞争力。
Colleagues and I analyzed recent trends in international migration of highly skilled workers – those with bachelor's degrees or higher – using a data set of unprecedented detail, extracted from LinkedIn, the social networking website for professionals.
我和同事们采用了叫领英网的职业社交网站上的数据集，分析了拥有学士学位或更高学位的高技术人才近期的移民趋势。
LinkedIn counts more than 200 million members in more than 200 countries and territories. People typically use their LinkedIn profiles to post their employment and educational history. That information provides the most comprehensive and up-to-date picture of the international flows of highly skilled migrants.
领英网拥有超过2亿的会员，分别来自200多个国家和地区。人们通常使用领英网上个人简介功能来发布他们的经历以及学历背景。这些信息提供了最全面的以及最新的高技术移民者国际流动走向。
Respecting the privacy of LinkedIn's members was a primary concern for us. We removed all personally identifiable information from our data set before conducting the study and only analyzed data in aggregate.
尊重领英网会员的隐私是我们首要考虑的问题。在开始我们的研究之前，我们从数据集中去除所有个人身份信息，仅分析整体数据。
The study leveraged various aspects of LinkedIn's Economic Graph – a digital map of the world economy based on member profiles – to understand trends in migration patterns. The research is the result of a collaboration between Bogdan State, who at the time was a Sociology PhD student at Stanford University, Mario Rodriguez, a Senior Data Scientist at LinkedIn, Dirk Helbing, a Professor at ETH Zurich and Emilio Zagheni, an Assistant Professor at the University of Washington, Seattle.
这项研究对领英网经济图谱的许多方面起到了杠杆作用-一幅基于会员简历的世界经济的数字地图-来理解移民模式的发展趋势。这项研究是由斯坦福大学社会学博士生Boqdan State，领英网高级数据科学家Mario Rodriguez，苏黎世联邦理工学院教授Dirk Helbing，以及西雅图的华盛顿大学助理教授Emilio Zagheni 共同合作的成果。
A topic ignored
被忽视的问题
Most of the public discussion on immigration reform has focused on the issue of undocumented immigrants living in the US and the potential consequences of highly-skilled immigrations on jobs and wages of Americans. Less attention has been paid, however, to the changing position of the United States as a destination of the world's most sought after migrants.
关于移民改革的大多数公众讨论集中在非法移民和高技术移民对美国的就业和收入的潜在影响之上。而越来越少关注在作为世界级移民目的地的美国的地位正在改变上。
Our study, which comes at a time when the country is mired in a divisive fight over such reform, counters conventional wisdom that the US is the incontestable top choice for professionals migrating from other countries.
当美国正陷于这样的改革争论中，我们的研究正逢时机的出现了，打破了美国是那些来自其他国家的专业人员无可争议的首选移民地的传统观点。
We tracked the proportion of migrants whose destination was the United States, out of all migrants observed during a particular calendar year, covering the period from 1990 to 2012. In our sample of LinkedIn users, we observed a slight increase of the fraction of migrants who went to the US during the 1990s, followed by a sharp downward trend after the year 2000.
我们追踪了自1990年至2012年那些移民美国的人口比例，而非特定的某一年内的。在那些领英网用户样本中，我们发现前往美国的移民人口在90年代期间有轻微增长，但2000年之后有显著下滑趋势。
While 27% of migrating professionals chose the US in 2000, just 13% did in 2012. The decline was seen across education levels, from bachelor's to doctorates. The biggest drop was among those in the science, technology, engineering and math fields, from 37% to 15%.
2000年有27%的移民专业人员选择了美国，但到了2012年只有13%。下降趋势充斥着整个学历层次，下至学士上至博士。最大的下降趋势影响在那些科学，技术，工程和数学领域，从37%跌至15%。
The biggest beneficiaries of the change were Asian countries, which witnessed the highest increase in professional migrants, attracting a cumulative 26% in 2012, compared with just 10% in 2000.
这个改变的最大获益者是亚洲国家，拥有最大幅度的专业技术移民增加，和2000年的10%相比，2012年吸引了累计26%的专业技术移民。
Increasing opportunities or a drop in demand?
创造机会或减少需求
The patterns that we observed could be tied to a variety of factors from improved career opportunities across the globe to a drop in demand for highly skilled migrants in the US or inefficiencies in its immigration system.
我们发现这个模式可能和多种因素有关，从增进全球就业机会到美国对高技术移民者的需求量下降或移民体系的不足。
During the first decade of the 21st century, for example, the US experienced two major economic crises: the collapse of the “dot-com bubble” from 1999 to 2001 and the financial crisis of 2008. These crises adversely affected opportunities for immigrants in the US.
在21世纪头10年中，举个例子，美国经历了两次重大的经济危机：1999至2001年间互联网泡沫的破裂，以及2008年经济危机。这些危机对美国的移民者有着不利的影响。
Nonetheless, our findings indicate more than a reaction to short-term crises. Long-term structural changes are taking place in the global system of employment-based, highly skilled migration.
尽管如此，我们的研究结果表明短期危机出现了不止一个反应。长期的结构改变正影响全球高技术人才移民就业体系。
Skilled immigrants have been a source of innovation and economic strength for the United States. One of the implications of the study is that, in the increasing global competition for talent, the US will have to work harder to attract and retain the world's best and brightest. That may be an issue Americans will have to ponder as they debate the best way to implement immigration reform.
技术移民已成为美国革新和经济力量的来源。这项研究表明在日益增长的全球人才竞争中，美国不得不更加努力的吸引并留住世界顶尖人才。正如他们为实施移民改革的最佳途径而争论那样，那可能会是美国人不得不仔细考虑的问题。