你以爲搬離貧民區就能脫貧嗎
Twenty years ago, federal poverty experts, inspired by the forceful arguments in the landmark book “The Truly Disadvantaged,” as well as by definitive research on the harmful effects of segregation, initiated a government experiment that moved 855 low-income predominantly African-American and Hispanic families out of public housing in poverty-stricken urban areas into less impoverished neighborhoods.
20年前，標誌性書籍《真正的窮人》(The Truly Disadvantaged)中強有力的論述，以及關於社羣隔離的負面效應的權威研究，使得聯邦貧困問題專家深受啓發，於是他們啓動了一項政府實驗項目，讓855戶低收入家庭從貧困城區的公租屋中搬到經濟狀況更好的社區。這些家庭絕大多數爲非洲裔和西語裔。
The results of the project have provoked an intense debate.
項目的結果引發了激烈爭論。Under the aegis of the “Moving to Opportunity” program, begun during the first administration of Bill Clinton, the Department of Housing and Urban Development randomly selected a large pool of low-income families with children living in public housing in Baltimore, Boston, Chicago, Los Angeles and New York. Ninety-eight percent of the families were headed by women; 63 percent were black, 32 percent Hispanic, and 3 percent white; 26 percent were employed, 76 percent were receiving welfare, and families had an average income of $12,709 in 2009 dollars.
該計劃名爲“搬向機遇”（Moving to Opportunity，簡稱MTO），始於比爾·克林頓(Bill Clinton)的第一個總統任期。當時，聯邦住房與城市發展部從巴爾的摩、波士頓、芝加哥、洛杉磯和紐約隨機選擇了一大批有小孩的低收入家庭。其中98%的家庭由女性支撐；63%爲黑人、32%爲西語裔、3%爲白人；26%有工作、76%領救濟，以2009年價格折算的家庭平均收入爲1萬2709美元（當時約合8.7萬元人民幣）。
These families, 4604 of them, to be exact, were then divided into three groups. An experimental group of 1,819 families was offered “Section 8 rental assistance certificates or vouchers that they could use only in census tracts with 1990 poverty rates below 10 percent”; 855 accepted the offer and became part of the study. A second group of 1,346 families was offered more traditional “Section 8” rent subsidy vouchers that could be used in any neighborhood; 848 accepted.
參與項目的共有4604戶家庭，分爲三組。一個實驗組有1819戶，政府向他們提供了“《住房法案》第8節規定的租賃補助券或代金券，但只能在1990年貧困率低於10%的人口普查區內使用”；855戶接受了提議，參與到這項研究中。第二組有1346戶，政府向他們提供的是更爲傳統的租賃劵，可以用在任何社區；848戶對此予以接受。A control group composed of 1,439 families stayed in public housing and became part of the study. The purpose of the relocation initiative, according to Department of Housing and Urban Development, was to test the “long-term effects of access to low-poverty neighborhoods on the housing, employment and educational achievements of the assisted households.” Researchers also studied how relocation affected the health of those who accepted vouchers.
此外還有1439戶家庭留在公租屋社區裏，成爲研究中的對照組。聯邦住房與城市發展部表示，這一搬遷項目的目的在於，測試“受助家庭進入低貧困社區後在住房、就業和教育成就方面的長期效應。”研究人員還研究了搬遷對領取租賃劵人員的健康影響。A paper published in the May 2013 issue of the American Economic Review, “Long-Term Neighborhood Effects on Low-Income Families: Evidence From Moving to Opportunity,” found that after 10 to 15 years, moving out of high-poverty public housing through the M.T.O. program showed mixed results.
《美國經濟評論》(American Economic Review)2013年5月刊發表了一篇題爲《低收入家庭的長期社區效應：以“搬向機遇”項目爲例》(Long-Term Neighborhood Effects on Low-Income Families: Evidence From Moving to Opportunity)的論文。文中發現，相關家庭通過MTO項目遷出高貧困公租屋社區的10到15年後，結果好壞參半。There were some positive developments, according to the primary author of the paper, Jens Ludwig, a professor of economics at the University of Chicago and the project director for a final assessment of the M.T.O. program. Ludwig and his six co-authors found improvement in “several key adult mental and physical health outcomes.” These included significantly lowered risk of diabetes and obesity, as well as an improved level of “subjective well-being.”
論文的第一作者芝加哥大學(University of Chicago)經濟學教授延斯·路德維格(Jens Ludwig)是負責MTO最終評審的項目主管。他表示，的確存在一些積極進展。他和六名論文合著者發現，受試者在“幾項關鍵的成人心理與生理健康指標”上有所進步，比如糖尿病與肥胖症的風險顯著降低，以及“幸福感”有所提升。But the Ludwig study also found that “changing neighborhoods alone may not be sufficient to improve labor market or schooling outcomes for very disadvantaged families.” Ludwig reported that this particular form of assistance from HUD –a housing voucher that allowed recipients to move into a “low poverty” area – had “no consistent detectable impacts on adult economic self-sufficiency or children’s educational achievement outcomes, even for children who were too young to have enrolled in school at baseline.”
不過，路德維格的研究還發現，“光是變動居住社區，或許並不足以改善底層家庭的就業或學業成就。”他在文中指出，這種允許家庭搬遷到“低貧困”地區的特殊租賃券“在一些方面沒有可觀察到的持續效應，不管是經濟上的自給自足，還是孩子的教育成就，就連實驗伊始年齡尚小、沒有入學的孩子也如此。”Ludwig reported similar findings in a follow-up essay published this week by Third Way, a Democratic think tank.
在民主黨“三維智庫”(Third Way)本週發表的一篇後續文章中，路德維格提出了類似結論。Some of the nation’s most prominent poverty researchers, including William Julius Wilson, a professor of sociology at Harvard and the author of “The Truly Disadvantaged,” consider that the design of the M.T.O. project was flawed, leading to unwarranted conclusions about the lack of improvement in employment and schooling.
美國的一些最爲權威的貧困問題研究者，比如哈佛社會學教授、《真正的窮人》的作者威廉·朱利葉斯·威爾遜(William Julius Wilson)認爲，MTO項目存在設計缺陷，從而引來了就業與學業方面未能有所改善的不妥結論。Wilson pointed out in an email to The Times that the families in the study who left public housing moved into segregated neighborhoods nonetheless, far from employment opportunities and with equally bad schools – often the same schools. Social conditions were only marginally better than those they had left.
在寫給《紐約時報》的電子郵件中，威爾遜指出，MTO項目裏離開公租屋的家庭還是搬到了隔離社區，遠離就業機會，而學校的糟糕程度也不相上下，子女往往還是去同樣的地方上學。他們的社會狀況只比之前好上一星半點。In addition, Wilson wrote, the adults in the program “had been exposed all their lives to the effects of severely concentrated disadvantage, and no matter how long they are followed in their new neighborhoods, the effects of those earlier years are not fully erased.”
此外，威爾遜寫道，參與項目的成年人“此前一生均過着極爲底層的生活，無論到新社區裏住了多久，早年所受的影響也不能完全消除。”Robert Sampson, a professor of sociology at Harvard, argued in a 2008 essay published in the American Journal of Sociology that the project should have been called “Moving to Inequality.”
在《美國社會學期刊》(American Journal of Sociology)2008年發表的一篇論文中，哈佛社會學教授羅伯特·桑普森(Robert Sampson)提出，MTO項目還不如叫做“搬向不平等”。Sampson pointed out in an email that many of the adults in the program had lived in extreme poverty for decades and that the children, who were on average 11 years old when they entered the program, had spent their early years living in adversity. “The result,” he wrote, “is that developmental effects are difficult if not impossible to study in the research design,” which does not reveal the “lagged effects of severe disadvantage.”
桑普森在寫給時報的電子郵件中指出，參與MTO項目的許多成年人本已在極端貧困中浸淫了幾十年，而他們的子女在項目開始的時候平均年齡爲11歲，也已經歷了早年的逆境。“結果，”他寫道。“在這樣的實驗設計之下，很難、甚至是不可能研究發展效應，”因爲這種設計沒有揭示出“嚴重貧困的滯後效應”。While the M.T.O. participants moved to neighborhoods with somewhat less poverty and crime, their new homes were by no means in flourishing sections of the city. Sampson produced a map of Chicago showing that the overwhelming majority of families moved to areas that still qualified as communities of “high concentrated disadvantage” based on a measure combining poverty rates, unemployment, welfare receipt, female-headed households, racial composition and density of children.
雖然參與MTO項目的家庭搬到貧困與犯罪狀況稍好的社區，其新家所處的地段絕不是什麼欣欣向榮之所。桑普森繪製了一幅芝加哥地圖，其中顯示，根據貧困率、失業狀況、領取救濟狀況、女性支撐家庭的數量、種族構成和兒童人口密度進行衡量的綜合指標，絕大多數MTO家庭遷去的地方仍是“底層人口高度集中”的社區。In a separate study, Heather Schwartz, a researcher at the RAND Corporation, reached conclusions more in line with Sampson’s and Wilson’s. Schwartz examined the performance of low-income, mostly minority students in Montgomery County, Md., an affluent majority-white suburb of Washington.
在另一項研究中，來自蘭德公司(RAND Corporation)的研究員希瑟·施瓦茨(Heather Schwartz)得出的結論也與桑普森和威爾遜更爲一致。在馬里蘭州蒙哥馬利縣，施瓦茨研究了大多爲少數族裔的低收入家庭學生的表現。該縣屬於華盛頓的郊區，經濟富裕，以白人居民爲主。The county adopted policies dispersing public housing so that many of the tenants, who were 72 percent black and 16 percent Hispanic, were housed in middle-class, largely white apartment complexes.
蒙哥馬利縣採用了讓公租屋散佈在各處的政策。租戶中，72%爲黑人，16%爲西語裔。按照這一政策，這些租戶住在以白人爲主的中產階級公寓樓裏。This allowed Schwartz to measure the performance of children from public housing who attended schools with large numbers of well-off white students, against the performance of those who attended schools with largely minority populations and much higher poverty rates.
這樣，施瓦茨就能夠將居住在公租屋裏的孩子的學業表現與大量來自富裕白人家庭的同學進行比較；對照組的孩子上的學校則大部分容納的是少數族裔學生，而且家庭貧困率要高得多。The results are striking. The low-income minority children from public housing all started with similar math scores. But after seven years, those who went to schools where fewer than 20 percent of their classmates were poor shot ahead of those who went to schools where 20 to 80 percent of their classmates were poor. This difference in trajectories is shown in Figure 1, in which the green line tracks math scores for poor children (defined as those receiving “free and reduced-priced meals” – a.k.a. FARM recipients) in relatively affluent schools, and the red line tracks math scores for poor children attending schools with much higher percentages of fellow students receiving FARM assistance.
結果相當驚人。住在公租屋的低收入少數族裔家庭的孩子，一開始的時候數學分數相當。但是七年之後，同學中貧困率少於20%的孩子，比起同學中貧困率在20%到80%之間的孩子，成績遙遙領先。圖1的曲線顯示了其中的差異。綠線代表那些上了較爲富裕學校的貧困家庭孩子（定義爲領取“免費和優惠餐”[FARM]的學生）的數學分數，紅線則代表所上學校裏領FARM比例要高得多的貧困家庭孩子的數學成績。Perhaps the most important factors in the intergenerational transmission of disadvantage are the long-term effects on infants of living in extreme poverty.
也許，貧困代際傳遞最爲重要的因素是，嬰幼兒時期極端貧困帶來的長期效應。A study published by the American Academy of Pediatrics in 2011, “The Lifelong Effects of Early Childhood Adversity and Toxic Stress,” shows that “early experiences and environmental influences can leave a lasting signature on the genetic predispositions that affect emerging brain architecture and long-term health.” The pediatric study links “early adversity to later impairments in learning, behavior, and both physical and mental well-being.”
美國兒科學會(American Academy of Pediatrics)2011年發表了一篇研究論文，題爲《嬰幼兒時期逆境與有害壓力的終生影響》(The Lifelong Effects of Early Childhood Adversity and Toxic Stress)。文中顯示，“早期經歷和環境影響可在遺傳傾向方面留下持久痕跡，從而影響正在成型的大腦構造和長期健康。”這項兒科研究認爲，“早期逆境與後來在學習、行爲及身心健康上的缺陷有關。”Early childhood stress affects the “developing architecture of the brain” in ways “that create a weak foundation for later learning, behavior and health.”
嬰幼兒時期的壓力會影響“大腦結構的發育”，從而“導致後來在學習、行爲和健康方面基礎薄弱。”Looked at this way, the M.T.O. findings — that participants who were given vouchers for housing in low-poverty neighborhoods made no gains in employment and wage equality compared with those left behind in public housing and that their children showed no improvement in school performance — do not seem surprising.
從這個角度看來，MTO項目的研究結果似乎並不意外。評估顯示，比起留在公租屋社區的家庭，拿到租賃券去低貧困社區居住的MTO參與者，在就業率與收入平等方面沒有進展，他們的子女的學業表現也並無進步。For one thing, participants appear to have been given little or no support other than modest housing counseling. But the issue is deeper than that: Multigenerational poverty is self-evidently more than a question of housing. It is unlikely to yield to even the best-intentioned one-dimensional approach.
首先，參與者似乎只獲得了不多的住房諮詢，此外幾乎沒有獲得其他支持。但更加深層的問題在於：多代貧窮可不僅僅是一個住房問題，這一點不言而喻。即便是最具善意的單一措施，也不可能解決得了它。Multifactorial approaches may be more productive. Recent papers such as “The Legacy of Disadvantage: Multigenerational Neighborhood Effects on Cognitive Ability” and “Neighborhood Effects in Temporal Perspective: The Impact of Long-Term Exposure to Concentrated Disadvantage on High School Graduation” are part of a continuing research agenda looking more profoundly into the causes of the intergenerational transmission of disadvantage.
綜合多種措施可能會更加有效。爲弱勢羣體境況代代相傳的現象，尋找更加深層的原因，這是一個持續進行的研究議程。最近的一些論文，比如《弱勢處境的傳承：居住多代的社區對認知能力的影響》 (The Legacy of Disadvantage: Multigenerational Neighborhood Effects on Cognitive Ability)和《從時間角度看居民區效應：長期處於弱勢境地對高中畢業狀況的影響》 (Neighborhood Effects in Temporal Perspective: The Impact of Long-Term Exposure to Concentrated Disadvantage on High School Graduation)，都屬於這個進程的一部分。The criticism of the M.T.O. study (which is now complete) points to new avenues for exploration. Even though the interpretation of the results of the housing voucher program has become contentious and somewhat politicized, the debate itself has the potential to be constructive.
MTO這項研究（目前已經完成）遭受的批評，指出了可供探索的一些新途徑。儘管對於租賃券計劃結果的解釋，變得富有爭議，而且有點政治化，這個辯論本身卻可能具有建設性。Significant change is possible, but more resources and more sophisticated research design will be a necessary next step.
巨大改變是有可能的實現的，但下一步需要投入更多的資源，進行更先進的研究設計。Lines of possible future inquiry include evidence-based evaluations of total-immersion school systems like the KIPP program and a better understanding of the effects of poverty on brain development. Perhaps most importantly, in the debate over “neighborhoods or schools,” would be a concentrated focus on reducing racial and ethnic discrepancies in test scores, according to the economists Roland Fryer Jr. of Harvard and Steven Levitt of the University of Chicago. Fryer and Levitt argue that the elimination of “the test score gap that arises by the end of junior high school may be a critical component of reducing racial wage inequality.”
未來可能要做的事情，包括對“知識就是力量”計劃(KIPP)等完全沉浸式學校系統進行以證據爲基礎的評估，以及更好地瞭解貧窮對大腦發育的影響。也許最重要的是，在“社區或學校”的討論中，把側重點放在縮小不同族裔的考分差異上，哈佛大學經濟學家小羅蘭·弗賴爾(Roland Fryer Jr.)和芝加哥大學經濟學家史蒂芬·萊維特(Steven Levitt)說。兩人認爲，在初中結束前消除考分差距，“可能會是減少種族工資不平等過程的一個重要組成部分。”The two authors write, “we demonstrate that in stark contrast to earlier studies, the black-white test score gap among incoming kindergartners disappears when we control for a small number of covariates.” They add, “There is suggestive evidence that differences in school quality may be an important part of the explanation. None of the other hypotheses we test to explain why blacks are losing ground receive any empirical backing.”
兩位作者寫道，“和早期的研究形成鮮明對比的是，我們的研究證明，當我們對少數協變量進行了控制後，黑人和白人進入幼兒園前的考分差距就消失了，”他們還表示，“這是一個暗示性的證據，顯示學校教學質量的差異，可能是導致考分差距形成的重要原因之一。我們也測試了用來解釋爲什麼黑人的成績每況愈下的其他假設，但它們沒有獲得任何實證的支持。”We have to figure out a better way to approach intervention, whether it’s education-based or neighborhood-based or both. Otherwise how can we interrupt the intergenerational transmission of disadvantage we are only beginning to understand?
對於弱勢境地代代相傳的情況，我們纔剛剛開始有所瞭解；必須找出一個更好的辦法，來對此加以干預，無論這個辦法是基於教育的，還是基於居民區的，還是雙管齊下。否則，我們怎樣才能阻止它繼續傳遞下去呢？
