指數(shù)基金的優(yōu)點(diǎn)眾所周知。它們的投資回報(bào)率往往高于主動(dòng)管理型共同基金,，部分原因是費(fèi)率較低,。這讓指數(shù)基金成為美國(guó)最受歡迎的投資方式之一。美國(guó)投資公司協(xié)會(huì)的數(shù)據(jù)顯示,，2015年1-11月流入指數(shù)基金的資金規(guī)模接近1450億美元,。同時(shí)，主動(dòng)型共同基金流失資金1610億美元,。但對(duì)我們這些受益者來(lái)說(shuō),，好處太多反而可能有害。

近期,，多項(xiàng)研究都得出了一個(gè)類(lèi)似的結(jié)論,。這些研究發(fā)現(xiàn)，指數(shù)基金規(guī)模的增長(zhǎng)正在逐步瓦解真正的股東精神,。出現(xiàn)這個(gè)問(wèn)題的原因在于,，指數(shù)基金是所謂的被動(dòng)型投資者，也就是說(shuō),，這些基金及其經(jīng)理人不挑選投資對(duì)象,。這項(xiàng)工作由創(chuàng)立相關(guān)指數(shù)的公司完成，比如標(biāo)準(zhǔn)普爾,。指數(shù)基金投資者只能隨波逐流,。

這樣的做法一直有助于提高投資回報(bào)率。許多研究都表明,，投資者買(mǎi)賣(mài)股票的時(shí)機(jī)往往有誤,，就連職業(yè)投資者也不例外。晨星最新的主動(dòng)/被動(dòng)投資晴雨表報(bào)告顯示,，主動(dòng)型基金的表現(xiàn)全面落后于被動(dòng)型基金,。在截至2014年底的10年時(shí)間里,，逾四分之三的美國(guó)主動(dòng)型大盤(pán)股基金的表現(xiàn)都不如同樣權(quán)重的被動(dòng)型基金群體。

這對(duì)散戶(hù)來(lái)說(shuō)可能是件好事,，但它不利于整體經(jīng)濟(jì)或整個(gè)市場(chǎng),。新的研究指出，隨著被動(dòng)型投資者的持股比例越來(lái)越高,，他們開(kāi)始改變公司的管理方式,。首先，公司將提案提交股東大會(huì)審議時(shí),，占比不斷增長(zhǎng)的被動(dòng)型股東也會(huì)行使權(quán)利,。盡管不采用主動(dòng)管理方式，但指數(shù)基金持有的股份仍有投票權(quán),。賓夕法尼亞州立大學(xué)學(xué)者彼得?伊利耶夫和米歇爾?勞里撰寫(xiě)的論文指出,，問(wèn)題在于這些基金更有可能作為一個(gè)團(tuán)體進(jìn)行投票，而傳統(tǒng)的主動(dòng)型基金“‘整齊劃一’地進(jìn)行投票的可能性較小”,。因此,，指數(shù)基金越多，就意味著在管理層之上的不同群體越少,。

其次,，沃頓商學(xué)院教授伊安?阿佩爾、托德?戈姆利和唐納德?凱姆在名為《被動(dòng)型投資者,，而非被動(dòng)型所有者》（Passive Investors, Not Passive Owners）的論文中指出，雖然指數(shù)基金不會(huì)盯著各位經(jīng)營(yíng)者,，但它們較有可能投票支持將權(quán)力從管理層手中收回的提案,。論文指出：“看來(lái)被動(dòng)型投資者的影響力來(lái)自于他們巨大的投票群體。被動(dòng)型股東的特點(diǎn)是不怎么支持管理層的提議,，但較為支持股東就治理問(wèn)題提出的建議,。”

對(duì)存在問(wèn)題的公司來(lái)說(shuō),，這是件好事,。但對(duì)于實(shí)際上擁有優(yōu)秀管理層的公司來(lái)說(shuō)，這會(huì)削弱管理者的權(quán)力,。由于被動(dòng)型基金沒(méi)能力挑選投資目標(biāo),，它們對(duì)待所有公司的方法似乎都一樣。

最后,，在同一行業(yè)中,，指數(shù)基金往往不僅持有一家公司的股票，它們的持股范圍還會(huì)覆蓋這家公司的大多數(shù)競(jìng)爭(zhēng)對(duì)手,。密歇根大學(xué)金融學(xué)助理教授馬丁?施邁茨和咨詢(xún)公司Charles River Associates高級(jí)合伙人何塞?阿扎爾以及伊莎貝爾?特庫(kù)共同撰文指出,，由此造成的局面是持股過(guò)于集中,，而且像貝萊德或Vanguard這樣的大型指數(shù)基金公司可以用被動(dòng)型基金持有的股票來(lái)投票。這會(huì)在相關(guān)行業(yè)引發(fā)反競(jìng)爭(zhēng)行為,。

比如說(shuō),，美國(guó)飛機(jī)票價(jià)上升11%的原因是追蹤標(biāo)普500指數(shù)的那些龍頭指數(shù)基金不光持有美國(guó)航空的股票，還持有達(dá)美航空和聯(lián)合航空的股份,。這樣的全面持股模式造成這些公司不太可能愿意跟對(duì)手展開(kāi)競(jìng)爭(zhēng),。如果這聽(tīng)起來(lái)還有些玄乎，那就用施邁茨的方法,，把這些航空公司比作街對(duì)角的兩座加油站,。如果所有者不同，它們也許就會(huì)相互壓價(jià),。然而,，“如果這兩座加油站都?xì)w你所有，你還會(huì)讓它們這樣做嗎,？很可能不會(huì),。”

施邁茨擔(dān)心,，缺乏競(jìng)爭(zhēng)會(huì)推動(dòng)消費(fèi)品價(jià)格上升,，從而削弱經(jīng)濟(jì)活力。此外,，其他研究還表明,，指數(shù)基金的結(jié)構(gòu)對(duì)股市來(lái)說(shuō)也是個(gè)問(wèn)題。

資產(chǎn)管理公司Osterweis Capital Management創(chuàng)始人兼首席投資官約翰?奧斯特維斯指出,，其中的原因在于指數(shù)基金采用市值權(quán)重法,。這種方法往往有利于那些規(guī)模最大的公司，而這些公司在最受歡迎的指數(shù)中占的比重也最大,，這就會(huì)產(chǎn)生“強(qiáng)者愈強(qiáng)”效應(yīng),。同時(shí)，隨著這些公司的市場(chǎng)價(jià)值不斷增長(zhǎng),，它們?cè)谥笖?shù)基金投資中占的比例也持續(xù)上升,。奧斯特維斯以今年上半年的回報(bào)率為例。他說(shuō),，在標(biāo)普500指數(shù)中,，最大的10只個(gè)股平均上漲了35%，而其余490只股票的平均跌幅幾乎達(dá)到7%,。

奧斯特維斯認(rèn)為,，由此產(chǎn)生的結(jié)果是，指數(shù)基金把自己的投資者困在了幾家公司里，而其他投資者也在購(gòu)買(mǎi)這些公司的股票,，這往往會(huì)造成后者股價(jià)過(guò)高,。他說(shuō)：“你買(mǎi)的股票可能會(huì)在一段時(shí)間里表現(xiàn)不佳，但最終你的投資收益也許會(huì)超過(guò)別人,，原因就是你可能沒(méi)有跳進(jìn)這些陷阱里,。”問(wèn)題在于,，指數(shù)基金的力量是否也讓經(jīng)濟(jì)進(jìn)入了這些陷阱之中,。（財(cái)富中文網(wǎng)）

譯者：Charlie

校對(duì)：詹妮

The virtue of index funds is well known. They tend to offer higher investment returns than actively managed mutual funds, in part because of their lower fees. That’s made them one of the most popular investments in America. Nearly $145 billion flowed into these funds in the first 11 months of the year, according to Investment Company Institute. At the same time, $161 billion flowed out of actively managed mutual funds. But perhaps we have gotten too much of a good thing.

That’s the conclusion of a number of recent research studies that came out this year. Their findings: The growth in the amount of money in index funds is chipping away at the true spirit of stock ownership. The issue has to do with the fact that index funds are so-called passive investors, meaning the funds and their managers don’t pick the companies they invest in. They are selected by an the company that creates the index, like Standard & Poor’s. And the investors have to go along for the ride.

That’s been good for investment returns. Many studies have proven, that investors, even professionals, tend to buy and sell at the wrong time. According to Morningstar’s most recent Active/Passive Barometer report, actively managed funds have generally underperformed their passive counterparts. More than three-quarters of active managers in the U.S. Large Cap category lagged the equal-weighted composite of their passive peers during the ten years ending December 31, 2014.

But what may be good for investors individually, may not be good for the economy or the market as a whole. As passive owners snag a larger and larger share of the companies in the market, they change how companies are managed, so the new studies say. First of all, their growing presence during proxy season wields power, when companies put up proposals to shareholder votes. And although they aren’t actively run, index funds still vote shares. The problem is index funds are more likely to vote as a group, according to a paper from Peter Iliev and Michelle Lowry at Penn State University. Traditional actively managed funds are “l(fā)ess likely to vote in a ‘one size fits all’ manner,” according to the paper. So more index funds means fewer disparate groups are keeping on top of management.

Second, while they aren’t watching individual managers, index funds are more likely to vote for provisions that take power away from managements, according to a papers from Wharton School professors Ian Appel, Todd Gormley, and Donald Keim, titled “Passive Investors, Not Passive Owners.”“Passive investors appear to exert influence through their large voting blocs—passive ownership is associated with less support for management proposals and more support for shareholder-initiated governance proposals,” the paper says.

That’s good for problem companies, but it can dilute the power of companies that actually have too good leaders. And passive funds, which don’t have the ability to chose, seem to treat all companies the same way.

Lastly, index funds tend to not just own one company in an industry, but most of their rivals as well. What happens, according to a paper Martin Schmalz, assistant professor of finance at University of Michigan wrote with Jose Azar and Isabel Tecu of Charles River Associates, is that stock ownership becomes too concentrated when companies like Blackrock or Vanguard, two large managers of index funds, vote the shares of passive funds. It can create anti-competitive behavior in an industry.

For example, U.S. airline tickets prices are 11% higher because the largest index funds that track the S&P 500 own not just American Airlines, but Deltaand United Continentalas well. And common ownership makes companies less likely to want to compete with rivals. If that sounds like hocus pocus, Schmalz likens it to two gasoline companies on opposing corners. If they have different owners, they might undercut each other’s prices. However, “if you own both gas stations on both sides of the street, are you still going to do the same thing? Probably not.”

Schmalz worries that a lack of competition is driving up prices for consumers and making the economy less dynamic. But other research suggests that the structure of index funds is a trouble for the stock market as well.

The reason John Osterweis, founder and chief investment officer of Osterweis Capital Management, says is because index funds are capitalization weighted. This dynamic often favors the largest companies, which make up the largest weights in the most popular index, and it has a momentum effect. And as those companies’ market value gets bigger, a greater percentage of the money index funds invest flow to those companies. Osterweis points to the returns in the first part of this year as an example. In the S&P 500, the top 10 contributors were up an average of 35%, while the bottom 490 stocks in the index were down almost 7%, he says.

The result, Osterweis says, is that investors through index funds get trapped in a few companies, and it’s the same companies everyone else is buying, so they tend to be over priced. “You might underperform for a period of time, but ultimately you might outperform because you might not be trapped in this thing,” says Osterweis. The question is whether index funds have become such a force that they have the economy trapped as well.