经济与社会科学2020nber.org
移民子女的社会向上流动性高于美国本土出生者
Children of immigrants have higher rates of upward mobility than US-born
入门 · 约 45 分钟读完前置知识：经济学基础、代际收入流动性概念
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这篇 NBER 论文研究美国移民子女与本土出生者子女的经济流动性差异，发现移民子女的向上流动性更高。评论者指出这可能源于选择偏差——移民本身是更有抱负、更努力的群体，以及移民父母因语言、学历认证等问题被"人为"压低了社会地位，子女的上升更像是一种"回归"。
HN 关注点：移民与经济流动性是美国社会长期关注的话题，讨论焦点在于这一结论是否反映移民群体的特殊性（选择偏差）而非移民政策或环境本身的优势。
HN 评论精选
这几条评论里：支持 1 质疑 2 补充 1
质疑移民群体存在选择偏差，高流动性可能只反映移民父母本身更有抱负和努力
我常提醒人们注意选择偏差。移民是独特的人群：他们不只是某个外国种族/国籍群体的成员，而是该群体中那些有抱负、有动力离开故土的人。举例来说，住在美国的加拿大人常被认为"和加拿大本土的加拿大人一样"，但往往不是——他们常常是那些无法融入加拿大文化、或被美国生活（至少是对美国生活的想象）深深吸引的人。所以这项研究其实是在说："有抱负、肯努力的父母的子女，向上流动性高于美国普通人群。"
maerF0x0查看英文原文
I often tell people to watch out for selection bias. Immigrants are a distinctly unique people. They're not just members of their foreign racial/national group, they're members of their foreign racial/national group with the ambitions/motivations to leave. To make the abstract concrete. Canadians living in the US are often thought to be "just like" Canadians living in Canada. But they're often not. Often they're the Canadians that sufficiently didnt fit into Canadian culture, or found something immanently attractive about US life (at least the perception of US life)... So this study is kind of saying "The children of ambitious and effortful parents have higher rates of upward mobility than the general populace of US people"
补充补充数据：亚裔美国人底层子女升至顶层收入的比例（27%）远高于白人（11%）
亚裔美国人（很多也是移民）的流动性数据特别有意思（见 equality-of-opportunity.org 的论文表1，第56页）：白人家庭中，父母处于收入最低四分位时，子女进入最高四分位的概率是11%（约为收入完全不相关时预期值的一半）；亚裔则接近27%。白人底层家庭的孩子留在底层的概率（28%）是升到顶层（12%）的约2.5倍；亚裔孩子升到顶层（27%）的概率反而是留在底层（12%）的约1.5倍。
rayiner查看英文原文
It's particularly interesting to look at the mobility statistics of asian americans (many of whom are also immigrants) as a category: http://www.equality-of-opportunity.org/assets/documents/race_paper.pdf. If you look at table 1 on page 56, you can see that for white americans, the probability of a child ending up in the top quantile of income where a parent is in the bottom quantile of income is 11% (about half the probability one would except of there was zero correlation between child and parent incomes). For Asian Americans its almost 27%. A white child born in the bottom quantile is about 2.5 times more likely to stay in the bottom quantile (28%) than to rise to the top quantile (12%). An asian child born in the bottom quantile is about 1.5 times more likely to rise to the top quantile (27%) than to stay in the bottom quantile (12%).
质疑移民的高流动性是"回归"其原有地位，而非真正的向上流动；原籍国的底层穷人并无此优势
这是因为移民由于语言差异、工作或学历不被承认等问题，社会地位和收入被"人为"压低了，他们只是在"反弹"。有些人在原籍国是专业人士，到了国外却做较低级别甚至体力活，子女会不断听到"我在老家是牙医，不是洁牙师"，这影响他们的自我认知。而在原籍国，真正出身贫困的人并没有同样的向上流动性——在有种姓或类种姓制度的地方尤其如此，曾曾祖父是谁仍决定你今天的地位。
kazinator查看英文原文
This is because people who immigrate are "artificially" pushed down in social status and income due to issues like differences in language, and not having some of your work or education experience recognized in the foreign country. These people are just "bouncing back". In some cases people who were professionals in their country of origin do relatively lower ranked or even menial work. Their children will be constantly reminded "I was a dentist back home, not a hygienist", which affects their self-image. Back in their home country, people who are actually from a poorer class do not experience the same upward mobility. That is all the more so in places that have caste or caste-like systems. Who your great-great-grandfather was still influences where you stand.
支持这一结论印证了大众的普遍直觉
这让我想起《我为喜剧狂》里 Jack Donaghy 的台词："多元化是驱动这个国家的引擎。我们是一个移民国家！第一代拼命干活，第二代上大学搞创新，第三代……玩单板滑雪、上即兴表演课。"感觉这是我们都一直默认为真的事情。
blakesterz查看英文原文
This reminds of a line from 30 Rock by Jack Donaghy: "Diversity is the engine that drives this country. We are an immigrant nation! The first generation works their fingers to the bone making things, the next generation goes to college and innovates new ideas, the third generation... snowboards and takes improv classes." Feels like one of those things that we all thought was true.
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