• 抗擊疫情vs.保衛經濟：生命能用金錢來衡量嗎？特朗普和美國商界領袖質疑，讓經濟停擺以遏制病毒是否明智。這本質上關乎一個社會如何評估經濟福祉與健康之間的取捨。應該衡量生命的經濟成本嗎？經濟學家們有話說。
抗擊疫情vs.保衛經濟：生命的價值能用金錢來衡量嗎？
EDUARDO PORTER, JIM TANKERSLEY2020年3月25日3月中旬的一個週五，西雅圖市中心幾乎空無一人。該地區已經成為新冠病毒在美國的灘頭陣地。 CHONA KASINGER FOR THE NEW YORK TIMES
[歡迎點擊此處訂閱新冠病毒疫情每日中文簡報，或發送郵件至cn.letters@nytimes.com加入訂閱。]
數十萬人死亡的代價，該如何衡量？
特朗普總統和商界領袖們越來越多地質疑，為遏制新型冠狀病毒的蔓延而讓美國經濟長期停擺是否明智——這種停滯已經讓數百萬人失去了工作。
“我們的人民希望重返工作崗位，”特朗普週二在Twitter上宣稱。他還說，“對策不應該比問題更糟（糟很多）！”
訂閱“簡報”和“每日精選”新聞電郵
同意接收紐約時報中文網的產品和服務推廣郵件
查看往期電郵 隱私權聲明
從本質上講，他提出了經濟學家長久以來努力解決的問題：一個社會如何評估經濟福祉和健康之間的取捨？
“經濟學家應該進行這種成本效益分析，”斯坦福大學(Stanford University)經濟歷史學家沃爾特·沙伊德爾(Walter Scheidel)說。“為什麼沒有人在一個月或一年的停擺帶來的經濟代價和由此拯救的生命之間做一個量化對比？整個學科完全有能力這麼做。但大家還是不願意冒這個險。”
一些支持取消當前經濟活動限制的經濟學家表示，州長乃至特朗普政府都沒有對這些限制的成本和效益做出充分評估。
“我們非常重視拯救生命，”芝加哥大學(University Of Chicago)經濟學家凱西·馬利根(Casey Mulligan)說，他曾在特朗普的經濟顧問委員會(Council of Economic Advisers)擔任過一年的首席經濟學家。“但這不是唯一的考量。這就是為什麼每次到了流感季，我們不會讓經濟停擺的原因。他們忽略了做事的代價。同時他們對能拯救多少生命也毫無概念。”
不過，經濟學家和公共衛生專家倒是普遍認為，取消這些限制將使更多的人死於這種病毒，付出巨大的代價，而且幾乎不會給經濟帶來什麼長期的好處。
密歇根大學(University Of Michigan)的經濟學家賈斯汀·沃爾弗斯(Justin Wolfers)表示：“引入成本效益框架是有幫助的，不過一旦你這樣做了，得到的結果將是壓倒性的，你無需更多細節就知道該怎麼做。”
沃爾弗斯說，只有在一種情況下，解除限制的好處會超過失去生命的代價，那就是“流行病學家在死亡的問題上對我們撒謊了”。
權衡人類生命的經濟成本似乎不可避免地顯得愚蠢。但是，社會也重視工作、食物和支付賬單的錢等事物，以及滿足其他需求和防止不相關的不幸的能力。
范德比爾特大學(Vanderbilt University)的經濟學家基普·維斯庫西(Kip Viscusi)表示：“讓人變窮也會對健康造成影響。”維斯庫西在他的學術生涯中一直利用經濟方法來評估政府監管的成本和收益。
失業者有時會自殺。如果窮人生病，他們死亡的可能性會更大。維斯庫西估計，在整個人口中，經濟每損失1億美元的收入，就會導致一起額外的死亡。
政府機構定期計算這樣的取捨。例如，美國環護署(Environmental Protection Agency)設定了一個標準，每拯救一個生命的成本約為950萬美元，將其作為是否清理有毒廢物場地的決定基準。
其他機構使用類似的方法進行量化評估，以決定是投資減少十字路口的事故，還是加強工作場所的安全標準。農業部有一個計算標準，用來估計食源性疾病的經濟成本——醫療保健、過早死亡、非致命病例造成的生產力損失。
曼哈頓休南區一條安靜的馬路。紐約州已下令關閉所有非必要的商舖。 HIROKO MASUIKE/THE NEW YORK TIMES
現在，一些經濟學家決定冒險把這種想法應用到冠狀病毒大流行上。
在周一發布的一篇論文中，西北大學(Northwestern University)的馬丁·S·埃辛鮑姆(Martin S. Eichenbaum)和塞爾吉奧·雷貝洛(Sergio Rebelo)，以及柏林自由大學(Free University)的馬蒂亞斯·特拉班特(Mathias Trabandt)使用了美國環保署的數字，分析在不造成經濟成本超過收益的情況下減緩疾病傳播的最佳方法。
即使沒有政府強制的封鎖，經濟也會急劇收縮，因為人們為防止傳染，會選擇遠離工作場所和商店。在這種情況下，埃辛鮑姆和同事們估計，到2020年，美國的消費者需求將減少8000億美元，降幅約5.5%。
根據流行病學預測，當病毒不受控制地傳播時會迅速擴大，感染半數以上的人口，然後群體免疫才會減緩其進程。假設感染者的死亡率為1%，那麼大約170萬美國人將在一年內死亡。
通過減少經濟活動來遏制病毒的政策，可以減緩病毒發展並降低死亡率，但它也將帶來更大的經濟代價。
埃辛鮑姆及同事們說，既考慮經濟損失又考慮生命的“最優”政策需要實施一些大大減緩經濟增長的限制措施。按照他們的評估方法，2020年，消費下降超過一倍，達到1.8萬億美元，但死亡人數減少了50萬人。這相當於每挽救一條生命就損失200萬美元的經濟活動。
在這種情況下，“你需要讓經濟衰退變得更糟，”埃辛鮑姆說。但一個重要的推論是，這種犧牲是有限度的：超過某個限度，為了拯救更多的人而失去更多經濟活動就不值得了。
他指出，這個模型在很大程度上依賴於其中的假設，它是為了表達取捨的量級。經濟學家們仍在作調整。如果考慮到醫療系統可能會被Covid-19的病例壓垮，從而增加死亡率，那麼成本效益比將會改變，因此會有必要以更快的速度實施更劇烈的封鎖措施。
歸根結底，這是在衡量生命的價值。
1960年代，諾貝爾經濟學獎得主托馬斯·C·謝林 (Thomas C. Schelling)提出讓人們為自己的生命定價。通過觀察人們願意花多少錢來減少死亡率——購買自行車頭盔、在限速範圍內行駛、拒絕購買附近存在有毒廢料的房屋，或者做工資更高、風險更大的工作——政府機構可以計算出一個標價。
不過，這可能會導致一些奇怪的數字。正如澳大利亞倫理哲學家彼得·辛格(Peter Singer)所指出的，在貧窮國家，兩三千美元就能挽救一條生命，然而他們仍然任由許多人死去。“和900萬美元比起來，”他說，“簡直不可思議。”
再納入死者的年齡，討論會變得更加敏感。它提出了一個問題：拯救一個80歲老人的生命，和拯救一個嬰兒的生命，有同等的價值嗎？
曾為奧巴馬政府工作的法律學者凱斯·桑斯坦(Cass Sunstein)是白宮負責這類評估的辦公室主任，他曾提議將政府政策的重點放在拯救生命時長上，而不是像其他國家的慣例那樣，僅僅關註生命本身。
“從這個意義上說，一個拯救年輕人的項目，比另一個同樣的拯救老年人的項目更好，”他寫道。
在喬治·W·布什(George W. Bush)政府時期，美國環保署曾試圖朝著桑斯坦喜歡的方向前進。為了計算監管發電廠煙塵排放的立法的成本和收益，它必須計算出降低過早死亡率的價值。它沒有像過去那樣，為每拯救一條生命估價610萬美元，而是採用了年齡折扣：70歲以上的人只佔年輕人生命價值的67%。
美國退休人員協會(AARP)等機構對此強烈反對。於是美國環保署放棄了這個想法。“我再說一遍，美國環保署不會在做決定時使用年齡調整分析，”當時的環保署負責人克里斯汀·托德·惠特曼(Christine Todd Whitman)辯稱。然而，在對所有人的生命一視同仁的同時，該機構無形中造成了年輕人剩餘生命的貶值。
無論老年人的經濟價值如何，Covid-19對他們來說似乎更致命。但特朗普週二宣布，在面臨最大風險的人得到保護的同時，經濟在未來三週內也會是“蓄勢待發”的狀態。“老年人將受到保護和關愛，”他在Twitter上寫道。“我們可以同時做到兩件事。”
Shutdown Spotlights Economic Cost of Saving Lives
President Trump and others have asked if halting normal life and commerce to fight the coronavirus is worth the cost. Here’s how economists figure it.
Downtown Seattle was virtually empty on a Friday in mid-March after the region became a U.S. beachhead for the new coronavirus.Credit...Chona Kasinger for The New York Times
By Eduardo Porter and Jim Tankersley
March 24, 2020
Can we measure the cost of hundreds of thousands of dead?
President Trump and leading business figures are increasingly questioning the wisdom of a prolonged shutdown of the American economy — already putting millions out of work — to curb the spread of the coronavirus pandemic.
“Our people want to return to work,” Mr. Trump declared Tuesday on Twitter, adding, “THE CURE CANNOT BE WORSE (by far) THAN THE PROBLEM!”
In essence, he was raising an issue that economists have long grappled with: How can a society assess the trade-off between economic well-being and health?
“Economists should be doing this cost-benefit analysis,” said Walter Scheidel, an economic historian at Stanford University. “Why is nobody putting some numbers on the economic costs of a monthlong or a yearlong shutdown against the lives saved? The whole discipline is well equipped for it. But there is some reluctance for people to stick their neck out.”
ADVERTISEMENTContinue reading the main story
Some economists who support lifting the current restrictions on economic activity say governors and even the Trump administration have not sufficiently assessed the costs and benefits of those restrictions.
“We put a lot of weight on saving lives,” said Casey Mulligan, a University of Chicago economist who spent a year as chief economist on Mr. Trump’s Council of Economic Advisers. “But it’s not the only consideration. That’s why we don’t shut down the economy every flu season. They’re ignoring the costs of what they’re doing. They also have very little clue how many lives they’re saving.”
Thanks for reading The Times.Subscribe to The Times
There is, however, a widespread consensus among economists and public health experts that lifting the restrictions would impose huge costs in additional lives lost to the virus — and deliver little lasting benefit to the economy.
“It’s useful to adopt the cost-benefit frame, but the moment you do that, the outcomes are so overwhelming that you don’t need to fill in the details to know what to do,” said Justin Wolfers, an economist at the University of Michigan.
The only case in which the benefits of lifting restrictions outweigh the costs in lost lives, Mr. Wolfers said, would be if “the epidemiologists are lying to us about people dying.”
Weighing economic costs against human lives will inevitably seem crass. But societies also value things like jobs, food and money to pay the bills — as well as the ability to deal with other needs and prevent unrelated misfortunes.
“Making people poorer has health consequences as well,” said Kip Viscusi, an economist at Vanderbilt University who has spent his career using economic techniques to assess the costs and benefits of government regulations.
Jobless people sometimes commit suicide. The poor are likelier to die if they get sick. Mr. Viscusi estimates that across the population, every loss of income of $100 million in the economy causes one additional death.
Government agencies calculate these trade-offs regularly. The Environmental Protection Agency, for instance, has established a cost of about $9.5 million per life saved as a benchmark for determining whether to clean up a toxic waste site.
Other agencies use similar values to assess whether to invest in reducing accidents at an intersection or to tighten safety standards in a workplace. The Department of Agriculture has a calculator to estimate the economic costs — medical care, premature deaths, productivity loss from nonfatal cases — of food-borne disease.
ImageA quiet stretch of SoHo in Manhattan. New York State has ordered all nonessential businesses to close.Credit...Hiroko Masuike/The New York Times
Now, some economists have decided to stick their necks out and apply this thinking to the coronavirus pandemic.
ADVERTISEMENTContinue reading the main story
In a paper released on Monday, Martin S. Eichenbaum and Sergio Rebelo of Northwestern University, with Mathias Trabandt of the Free University in Berlin, used the E.P.A.’s number to figure the optimal way to slow the spread of the disease without economic costs that exceed the benefits.
The economy would contract sharply even without a government-imposed lockdown as people chose to stay away from workplaces and stores, hoping to prevent contagion. In that case of voluntary isolation, Mr. Eichenbaum and his colleagues estimated that U.S. consumer demand would decline by $800 billion in 2020, or about 5.5 percent.
Based on epidemiological projections, as the virus ran unchecked, it would quickly expand to infect somewhat over half the population before herd immunity would slow its course. Assuming a death rate of about 1 percent of those infected, about 1.7 million Americans would die within a year.
A policy to contain the virus by reducing economic activity would slow the progression of the virus and reduce the death rate, but it would also impose a greater economic cost.
Mr. Eichenbaum and his colleagues say the “optimal” policy — assessing economic losses alongside lives — requires restrictions that slow the economy substantially. Under their approach, the decline in consumption in 2020 more than doubles, to $1.8 trillion, but the deaths drop by half a million people. That would amount to $2 million in lost economic activity per life saved.
In this instance, “you want to make the recession worse,” Mr. Eichenbaum said. But an important corollary is that there are limits to the sacrifice: Beyond a certain point, it would not be worth it to lose more economic activity in order to save more people.
The model, he noted, is heavily dependent on the assumptions that go into it, meant to convey the magnitude of the trade-offs. And the economists are still tweaking. The cost-benefit ratio will change if one considers that the health system might become overwhelmed by Covid-19 cases, increasing mortality rates. That would justify a more aggressive lockdown that ramped up more quickly.
ADVERTISEMENTContinue reading the main story
It comes down to what a life is worth.
In the 1960s, a Nobel Prize laureate in economics, Thomas C. Schelling, proposed letting people price their own lives. Observing how much they were willing to spend to reduce their odds of death — by buying a bicycle helmet, driving within the speed limit, refusing to buy a house near a toxic-waste site or demanding a higher wage for a more dangerous job — government agencies could compute a price tag.
That can lead to some strange numbers, though. As Peter Singer, the Australian ethical philosopher, noted, you can save a life in poor countries with $2,000 or $3,000, and many of those lives are still allowed to be lost. “If you compare that with $9 million,” he said, “it’s crazy.”
The discussion gets even more touchy when one considers the age profile of the dead. It raises the question: Is saving the life of an 80-year-old as valuable as saving the life of a baby?
Cass Sunstein, a legal scholar who worked for the Obama administration, heading the White House office in charge of these valuations, once proposed focusing government policies on saving years of life rather than lives, as is customary in other countries.
“A program that saves younger people is better, in this sense, than an otherwise identical program that saves older people,” he wrote.
In the George W. Bush administration, the E.P.A. tried to move in Mr. Sunstein’s preferred direction. To calculate the costs and benefits of legislation regulating soot emissions from power plants, it had to figure out the value of reducing premature mortality. Rather than evaluate every life saved at $6.1 million, as it had done in the past, it applied an age discount: People over 70 were worth only 67 percent of the lives of younger people.
The backlash by AARP and others was fierce. And the agency dropped the idea. “E.P.A. will not, I repeat, not use an age-adjusted analysis in decision making,” pleaded Christine Todd Whitman, the E.P.A. administrator at the time. Yet by putting the same price on all lives, the agency implicitly devalued young people’s remaining years.
ADVERTISEMENTContinue reading the main story
Covid-19 seems to be much more lethal for older people, whatever their economic worth. But Mr. Trump declared Tuesday that even while those most at risk are safeguarded, the economy could be “raring to go” within three weeks. “Seniors will be watched over protectively & lovingly,” he said on Twitter. “We can do two things together.”
Economic Costs of the Coronavirus
Trump Considers Reopening Economy, Over Health Experts’ ObjectionsMarch 23, 2020
Coronavirus Recession Looms, Its Course ‘Unrecognizable’March 21, 2020
Coronavirus Cost to Businesses and Workers: ‘It Has All Gone to Hell’March 15, 2020
Eduardo Porter joined The Times in 2004 from The Wall Street Journal. He has reported about economics and other matters from Mexico City, Tokyo, London and São Paulo. @portereduardo
Jim Tankersley covers economic and tax policy. Over more than a decade covering politics and economics in Washington, he has written extensively about the stagnation of the American middle class and the decline of economic opportunity. @jimtankersley
A version of this article appears in print on March 25, 2020, Section B, Page 1 of the New York edition with the headline: Hard Math: Economic Costs Of Saving Lives. Order Reprints | Today’s Paper | Subscribe
沒有留言:
張貼留言