诺奖背后是拼爹？MIT最新研究：读博不能突破阶层天花板

教育通常和阶层跃升密切挂钩。很多人相信，接受良好的教育可以打破家庭背景的桎梏，开启更广阔的人生道路。

但事实上，家庭的社会经济地位、文化背景和地域差异依然深刻影响着每个人的教育机会和职业前景。

对于没有丰富资源和机会的中产孩子来说，实现阶层跃升到底要靠什么？

最近，麻省理工学院的一项研究清晰地揭示了一个残酷的事实：普通家庭的孩子，即使博士毕业，也很难突破阶层。

这项研究深入分析了1993年至2021年间美国博士生毕业后的成就，结果发现，背景较差的博士毕业生在研究型或排名靠前的学校获得终身教职的机会，显著低于背景更好的同龄人。

具体而言，第一代大学毕业生获得终身教职的可能性比父母没有博士学位的人低13%。

这表明，即使在控制了种族、性别、学科和学校等多种变量后，博士生的原生家庭背景依然对他们的职业成就有重大影响。

研究发现，父母阶层越高，博士生在职场上的成就越显著。这一趋势在理工科和社会科学领域均得到了验证。

尽管获得博士学位通常被视为一种文化资本，赋予个人在学术和职业生涯中更高的竞争力，但这种文化资本并未能有效转化为经济资本和社会资本。

也就是说，在某种程度上，即使获得博士学位，家庭的社会经济地位依然在很大程度上决定了个人的职业路径。

另外，研究还发现，出身于精英阶层的博士生在职场中往往表现出一种“松弛感”。这种“松弛感”使他们能够更轻松地与导师交流，建立良好的职业网络。

而跨越阶层的博士生在职场中则显得更加谨慎，常常需要在与人交往时更加小心翼翼。

这种微妙的差异不仅影响了他们的职场适应性，也可能导致心理上的不适应和孤独感。

这一发现为理解博士生在职场中所遭遇的挑战提供了一种新的视角。

那些来自较低社会经济背景的博士生在追求职业成功的过程中，常常需要付出更多的努力，但相应地，他们也可能会面临更多的挫折和困难。

研究显示，在工业领域工作的博士，薪酬和管理职责之间的阶级差距在整个职业生涯中持续扩大。

这一现象表明，在美国的不同行业中，职业发展的阶级差距依然存在，凸显了社会经济背景对个人职业路径的深远影响。

无论是在学术界还是工业界，出身的差异一直都存在，形成了一个难以打破的阶层鸿沟。

随着诺贝尔奖的公布，一项关于诺贝尔奖得主家庭背景的研究也引起了广泛关注。

来自普林斯顿大学、宾夕法尼亚大学沃顿商学院、达特茅斯学院以及帝国理工学院的四位研究人员联合进行的这项调查，分析了自1901年至2023年间715位来自44个国家的科学类诺贝尔奖得主（排除了和平奖和文学奖）的家庭背景。

研究的重点在于分析这些诺贝尔奖得主父亲的职业和收入，并探讨顶级科学家的出身与其成就之间的关系。

结果显示，约50%-60%的诺贝尔奖得主来自于收入和教育水平排名前5%的家庭，也就是经济和社会地位非常高的家庭。

这种经济和社会地位不平等现象也体现在性别的差异上。

在715位诺奖得主中，女性仅有28位，她们的家庭背景通常更加精英，父亲的收入和教育水平普遍高于男性诺奖得主的家庭。

分析还进一步揭示，诺贝尔奖得主的父亲中，最常见的职业是企业主，占比高达15.36%；

其次是物理学家和医生，教授、讲师和工程师紧随其后。

这些职业不仅伴随着高社会地位和丰厚收入，其父母的教育水平普遍较高，为孩子进入科学领域提供了得天独厚的资源优势。

与之形成鲜明对比的是，只有3%的诺奖得主是在农场长大的，例如今年医学奖得主维克托·安布罗斯。

这一研究不仅揭露了科学界资源分配的不均，更是对“龙生龙，凤生凤，老鼠的儿子会打洞”这句老话的有力佐证。

尽管从1901年到2023年间诺贝尔奖得主的社会经济背景呈现出多样化的趋势。

普通阶层的孩子获奖的机会不断增加但整体趋势还是比较缓慢，大多数诺贝尔奖得主依然来自精英家庭。

出生于普通家庭的孩子，想要在科学领域取得成功的机会微乎其微。

尽管很多出身普通的孩子潜力巨大，甚至能够与诺贝尔奖得主相媲美，但迫于生计压力，他们往往不得不投入大量时间和精力在工作上。

这剥夺了他们专注于科研的机会，最终能够在科学领域绽放光彩的已经是凤毛麟角。

伦敦经济学院社会学教授Sam Friedman在其著作《阶层天花板》中深入探讨了跨越阶层的精英在职场中所面临的各种困境，揭示了社会阶层对职业发展的深刻影响。

他与美国斯沃斯莫尔学院的助理教授Daniel Laurison的研究表明，在英国的精英职业中，存在显著的“阶级薪酬差距”。

即使是那些来自工人阶级背景的人成功进入了有声望的工作，他们的收入平均仍比来自特权背景的同事低16%。

Friedman在另一篇文章中进一步指出，跨越的阶层越远，个人所面临的情绪代价越高，孤独感也越强，这些因素都造就了阶层跃升的困难。

这说明跨越阶层难以实现背后的原因，不仅在于个人努力，更在于家庭背景。

反观当下的教育，中产父母往往重视教育，并愿意为孩子投入大量资源，但是实际上，中产孩子成长无形中已经被设置了“天花板”。

中产父母经济相对稳定，却缺乏突破性的机会与资源，这直接影响到孩子未来的发展道路。

更为隐秘的障碍是，中产阶级的孩子容易被困在“恐惧失败”的心理束缚中。

中产父母往往希望孩子能够“稳扎稳打”，不支持他们冒险或追求一些不切实际的梦想和挑战。

这种谨慎态度让孩子缺乏挑战自我的勇气，久而久之，他们可能会安于现状，失去改变命运的动力。

在职业发展上，这些孩子也面临明显局限。

由于家庭背景，他们通常追求“稳妥”的职业，比如医生、律师、教师、公务员等，但这些领域竞争异常激烈，且发展路径相对固定，缺乏灵活性与创新空间。

在许多高端职业中，人脉关系至关重要，而中产家庭的孩子由于社交圈子限制，往往难以获得这些关键资源，在职场上处于劣势。

中产阶级的孩子在教育与职业发展中，虽然表面上起点较好，但却受到家庭背景、心理因素和社交资源的多重限制。

这不仅影响他们的职业选择，也制约了他们的潜力发挥。

中产孩子突破阶层虽然困难重重，但并不代表没有未来。

斯坦福大学经济学教授Ran Abramitzky和普林斯顿大学经济学教授Leah Boustan在合著的《黄金街道：美国不为人知的移民成功》中指出，移民的孩子往往更能实现阶层跃升。

研究显示，移民子女不仅超越父辈的概率更高，他们在社会阶层中的“向上流动”比例也显著高于美国本土的同龄人。

那么，为什么移民子女能够实现这一点？研究者们总结了几个关键因素：

首先，移民家庭对教育的重视程度极高；其次，移民子女从小目睹了父辈的奋斗与努力；最后，为了寻求更好的发展机会，新移民往往愿意迁移到经济更发达的地区。

从中，我们可以得到几点启发：

第一，教育至关重要。

对于中产家庭而言，提供良好的教育几乎是可以实现的。

但是，家长应避免让孩子过早陷入“路径依赖”的思维，更不能被“稳妥”路线所限制。

而是应该鼓励他们去发展多样的兴趣和职业可能性，培养他们的创新和探索精神。

第二，提供全球视野和多元文化体验。

在全球化的时代，仅依赖家庭本身的资源和机会已经很难立足。

父母可以通过国际教育、海外交流、语言学习等方式，帮助孩子拓宽视野，增强他们在全球竞争中的优势。

第三，鼓励孩子敢于冒险，勇于试错。

尝试和努力后可能会遭遇失败，这确实会让人走弯路，但正是通过不断的试错，才能发现更好的选择、开阔更广的视野，发现自己突破阶层的人生机会。

我们也要认识到阶层跃升并非成功的唯一定义，更重要的是能够不断探索自己的可能性，追寻自己的梦想，并找到自己愿意投入一生的事业。

唯有勇敢、坚持与创新，才能使他们在复杂的社会环境中，找到属于自己的价值。

Sourced from MIT News-What Is the Recipe for Social Mobility? | alum.mit.edu

The United States is a land of opportunity, but it’s a complicated thing. People in the workforce today are much less likely to earn more than their parents did, compared to people born around 1940. Some parts of the country generate much more economic mobility than others. And even with other matters being equal, there are still large differences in mobility among racial and ethnic groups.

Professor Nathaniel Hendren PhD ’12 has spent the last decade studying these matters. An economist who just joined the MIT faculty this summer, Hendren has co-authored a series of published papers with important empirical results shedding light on the conditions of opportunity in the United States today.

For instance, 92 percent of people born in 1940 earned more than their parents, but only 50 percent of those born in 1984 are doing so, with the middle class experiencing the biggest change. This is only modestly due to changes in the rate of GDP growth, the research shows, and is much more because of the way income inequality has grown, restricting middle-class gains.

Where people live affects their prospects, too. A child in the bottom quintile of the national income distribution growing up in San Jose, California, is about three times more likely to reach the top quintile than a bottom-quintile child in Charlotte, North Carolina. All of this interacts with race and ethnicity; even when accounting for levels of parental income, Black boys will have lower incomes in adulthood than white boys will in 99 percent of US census tracts.

“It opens up a lot of questions about what historical [issues and] policies have done, and how they led to low income mobility today,” Hendren says. “It is a landscape that is affected by our institutions and policies.”

And by our places. Hendren’s research has shown there is a neighborhood-level impact on economic outcomes, one that corresponds to the number of years children live in a particular place.

“We are sort of a weighted average of the neighborhoods we grew up in,” Hendren says.

To be sure, many policies aim to provide better opportunities for people. In another area of his research, Hendren has developed new tools for comparing the usefulness of programs, while serving as founder and co-director of Policy Impacts, a nonpartisan group supporting evidence-based policymaking.

“Historically, over the last 50 years, the policies that provide the biggest returns are those that make direct investments in kids, especially low-income kids,” Hendren says. “It’s not necessarily cash transfers to their parents or things that might spill over. It's investments in their schools, their health, direct investments in those kids.”

Off to the Races

Hendren’s arrival in the faculty ranks at MIT represents an intellectual homecoming, given that he earned his PhD at the Institute. His interest in the field began to flower as an undergraduate at the University of Chicago, though, where he double-majored in math and economics.

“I always liked that you can be formal about describing social interactions or human behavior with math, and that the precision of math disciplined the theories that you have and the statements you can make,” Hendren says.

After joining the doctoral program at MIT, Hendren worked with Daron Acemoglu and Amy Finkelstein as his primary advisors, producing a thesis with research on insurance markets.

“I came here and just never looked back. I found I enjoyed doing research, and it was off to the races at that point,” Hendren says.

Hendren has been producing notable research at racing speed ever since. As a newly minted Institute PhD in 2012, Hendren joined the faculty at Harvard University and soon started focusing on matters of opportunity and social mobility. Working with a series of co-authors, including Raj Chetty, Lawrence Katz, and Emmanuel Saez, he has published over two dozen papers in major journals.

Hendren has also co-authored some papers with Finkelstein on the impact of health insurance programs, and he sometimes studies market failure issues. But much of his work has centered directly on social mobility, including research designed to test individual policy ideas.

In one 2016 paper, Chetty, Hendren, and Katz examined the Moving to Opportunity program, which gives poor families vouchers to help with housing in lower-poverty neighborhoods, and found that children in families participating in the program eventually realized 31-percent gains in income as adults.

In a related paper, forthcoming in the American Economic Review, Chetty, Hendren, Katz, MIT economist Christopher Palmer, and additional co-authors ran an experiment with a housing voucher program in the Seattle area. By supplying low-income families with a “navigator” who provided some of the services of a real estate agent and financial advisor, participants’ use of the vouchers increased from 15 percent to 53 percent.

“We found remarkably large effects when you provide people with these navigators,” Hendren notes. “It’s a pretty low-touch intervention for such a large life change.”

That kind of result, Hendren notes, “rules out this story about how [housing] segregation is driven by the preferences of the segregated. I think it’s driven by the constraints imposed on them by institutions, and people [altering] the rules of the game.” He adds: “Our results suggest that a lot of people want to live in neighborhoods that promote higher upward mobility for their kids, and are willing to make tradeoffs to do that.”

Measuring What Works

Historically, Hendren notes, residential segregation has been embedded in sweeping currents in American life; even when millions of Black families left the segregated Jim Crow South during the so-called Great Migration in the mid-20th century, their arrival in northern cities caused extensive “white flight” from cities to suburbs. Individual programs like Moving to Opportunity can work, but there are large-scale hurdles to creating sustainably diverse communities that enourage social mobility.

“Our results suggest we create places with high upward mobility, but they are enclaves with barriers that prevent [many] people from accessing those places,” Hendren says.

And yet, given that governments have created a wide array of measures designed to encourage education, economic advancement, public health, a cleaner environment, and many other things that can influence social outcomes, Hendren in recent years has been working to redefine the bottom-line measurement of those programs.

“We’re trying to create coherent, consistent measures of what a policy does,” Hendren says. Studies across topics from education to the environment to public health use differing metrics to evaluate policies, but Hendren and economist Ben Sprung-Keyser have worked to align them in a common framework,  developing a metric they call “the marginal value of public funds” and applying it to 133 different types of government policies.  

“It’s really a simple metric,” Hendren says. “For every dollar the government spends on a policy on net, how much benefit does the policy provide to its beneficiaries in dollar terms?”

This is the research showing that spending on lower-income children provides the biggest additional return per dollar spent. Which is not to say that other programs are not worthy. But policymakers can use this kind of analysis in allocating their budgets.

To be sure, even clearly effective policy ideas can struggle to make it through any given legislative chamber. Still, Hendren notes, it is valuable to have the solid, firm facts and opportunity, mobility, and policy on hand for everyone to use.

“Politics is sticky and messy,” Hendren says. “My view of social change and politics is maybe a little rosy and optimistic, but if I don’t have that view, I won’t stay motivated. If we can measure the tradeoffs that we think are true, based on our best estimates, and shine a light on the implicit preferences that a politician has to support one policy over another, then I think we can make a little bit of progress.”

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