華爾街的投資者很少提及十分關(guān)鍵的問題：如果企業(yè)利潤比經(jīng)濟增長快，利潤增長能否持續(xù)？這是一種新常態(tài)，還是會像過去一樣，這種吞沒GDP的趨勢會逆轉(zhuǎn)，今天破紀錄的漲勢會再度變成一場潰敗？

股東們要小心了。推動股價上漲的動力源自于利潤從整體經(jīng)濟中分離出來，而這種動力目前正在面臨風險。要么市場的正常漲跌會把股票價值拉回其正常情況下在GDP中所占的份額，要么美國國會可能會采取行動，攻擊大型科技公司，要求把現(xiàn)在流向股東的獎金更多地分給工人。無論如何，美國的公司和經(jīng)濟是一體的。從長期來看，他們需要保持步調(diào)一致。如果二者偏離太遠，要想重新恢復(fù)平衡可能會導(dǎo)致股價重創(chuàng)。

標普500指數(shù)自從2016年末以來的出色表現(xiàn)，全都因為盈余。當年第四季度以來，以之后12個月的一般公認會計原則盈余為基礎(chǔ)的盈利增長了41%，達到每股盈余134.39美元的井噴式歷史紀錄。在此期間，就像貼在信件上的郵票一樣，股價緊隨盈余的增長而上漲，漲幅完全相同，上升到3000出頭。這是因為投資者一直讓股票的市盈率保持在22至24倍之間。

但關(guān)鍵是要評估，盈利泡沫是否已經(jīng)將股價推高至無法持續(xù)的高位。

為了判斷這種情況是否真的已經(jīng)發(fā)生，我們要看看股票價格正處于哪個區(qū)位，是過分便宜還是貴得危險。其中最好的衡量方式之一是總市值（TMC）和國內(nèi)生產(chǎn)總值（GDP）之比，總市值是指即美國所有上市公司的價值，國內(nèi)生產(chǎn)總值為美國國內(nèi)每年生產(chǎn)的所有商品和服務(wù)的價值。簡單地說，該指標顯示了股票市場的價值在經(jīng)濟中所占的份額。

如果股票價值在全國收入中所占的比例遠高于平均水平，很可能意味著，過高的股票收益吞噬掉了過大比例的國民收入，留給工資的份額就更低。今天的情況確實如此。過去，商品競爭和勞動力競爭的引力作用總是能夠通過抑制超額利潤來恢復(fù)平衡，在大多數(shù)情況下，還會壓低股價。

股市總價值與GDP之比是沃倫·巴菲特最喜歡的指標，他說：“無論任何時候，這可能都是判斷當前股市估值的最佳指標。”（下文我們把這個指標稱為“證券化率”。）

如今，所有股票的價值與國民收入之比為146.4。這是過去半個世紀以來的第二高，僅次于2000年3月30日互聯(lián)網(wǎng)泡沫頂峰時期的148.5。過去十年里，該數(shù)字平均維持在80左右，所以現(xiàn)在已經(jīng)超過了基準線約80%。

過去50年的證券化率浮動很大，但通常會在大幅上漲或下跌后回到80的平均水平。從這個指標的定義來看，每一段從80開始到80結(jié)束的時期，收入都會隨著GDP的增長而增長。（我們指的是名義GDP，而不是經(jīng)過通脹調(diào)整后的數(shù)字。）盡管如此，研究中間傾斜的過程還是很有幫助的。

我們從1971年年初達到80的時間點開始。在1982年的大衰退中，證券化率曾經(jīng)降至35，在1976年至1986年期間，基本維持在50以下。這一數(shù)字直到1995年年底才重回80，總共花費了25年。在此期間，標普500指數(shù)平均每年上漲7.3%，反映出20世紀70年代和80年代初石油沖擊引發(fā)的高通脹推高了經(jīng)濟增長。

從1995年年底到2000年3月30日，證券化率從80大幅飆升，上漲86%，達到了互聯(lián)網(wǎng)熱鼎盛時期近150的歷史最高紀錄。然后，市場引力開始起作用，到2003年4月，證券化率跌回80。在這7年多的時間里，標普500指數(shù)以5.6%上下的正常速度上漲，速度是過去5年的一半，再一次和GDP保持一致。

該比率從2003年年初的80，跌至2009年金融危機期間的50低點，直到2011年10月才再次達到80。在這七年半的時間里，由于房價暴跌拖累了經(jīng)濟，標普500指數(shù)每年僅上漲3.1%。

自2011年年底回歸“正常”水平以來，證券化比例一路狂飆，瘋漲至目前的146.2，而在此過程中只出現(xiàn)了輕微波動。在這7年9個月的時間里，GDP增長了35%，從15.6萬億美元增長到21.1萬億美元。股市總價值漲幅主達148%。標普500指數(shù)的年增長率為11%，而國民收入的增長速度還不到它的一半，僅為4%。

簡而言之，企業(yè)削減了員工數(shù)量、壓低了工資、享受著低息貸款帶來的福利，除此之外，還從平靜的市場中獲益。這些趨勢完全超過了平庸的經(jīng)濟增長。

另外兩項指標正在閃著紅燈。傳奇經(jīng)濟學家米爾頓·弗里德曼2006年去世之前，我經(jīng)常采訪他。弗里德曼告訴我，“從長期來看，盈余占國民收入的比例不可能長期高于歷史平均水平。”這位諾貝爾獎得主還宣稱，盡管盈利表現(xiàn)在長期內(nèi)決定了企業(yè)的價值，但“短期市場遠不能稱為‘有效市場’”，這意味著股票價格可能與企業(yè)的潛在價值存在顯著差異。

如今，根據(jù)圣路易斯聯(lián)邦儲備銀行（St. Louis Federal Reserve）的數(shù)據(jù)，企業(yè)盈利占GDP的9.2%。這比半個世紀以來7%的平均水平高出三分之一。由于利潤通常會像弗里德曼所說的那樣“回歸均值”，這一差距注定會縮小。營業(yè)利潤率看起來也高得無法持續(xù)。根據(jù)標普數(shù)據(jù)，過去四個季度標普500指數(shù)公司的平均漲幅為11.25%，比前30個季度9%的平均漲幅高出25%。

可以想象，我們的經(jīng)濟確實已經(jīng)發(fā)生了變化，正如美國國會中主張拆分科技股的人士所言，互聯(lián)網(wǎng)使科技巨頭實施壟斷經(jīng)營。包括前財政部部長拉里·薩默斯在內(nèi)的許多有影響力的經(jīng)濟學家都認可這種立場。另一種可能性是：由于這些公司利潤豐厚，著急的初創(chuàng)企業(yè)都以此類公司主要目標，大公司的盈利能力最終將被侵蝕。

最好的辦法是讓股票估值占國民收入的份額回歸正常。過去幾年看起來像是每隔幾十年就會發(fā)生的那種瘋狂脫鉤，而不是從全球競爭最激烈的市場向卡特爾網(wǎng)絡(luò)轉(zhuǎn)變的結(jié)構(gòu)性下行。

市場在控制失控的利潤上還從未失手，這次也同樣不會失敗。（財富中文網(wǎng)）

譯者：Agatha

Here’s a crucial question for investors that the Wall Street crowd seldom addresses: Can corporate profits keep booming by growing faster than the economy? Is this the new normal, or will the GDP-gobbling trend reverse, as it always has in the past, turning today’s record-shattering rally into a rout?

Shareholders beware. It’s the unhinging of profits from the overall economy that has been propelling stock prices, and that dynamic is now in danger. Either the normal ebb and flow of markets will pull equity values back to their traditional share of GDP, or Congress is likely to do the job by attacking Big Tech and mandating that workers get a lot more of the bounty now flowing to shareholders. Either way, America’s companies and its economy are one in the same. Over the long-term, they need to move in tandem. And if they stray too far apart, getting back to balance can pummel share prices.

The S&P 500’s fantastic performance since late 2016 is all about earnings. Since the fourth quarter of that year, profits, based on the trailing twelves months of GAAP earnings, have jumped 41% to a blowout record of $134.39 per share. In that period, share prices have followed earnings like a postage stamp on a letter, rising precisely the same number to just over 3000. That’s because investors are awarding shares a consistent P/E multiple in the 22 to 24 range.

But it’s critical to assess whether or not a profit bubble has driven shares to unsustainably high prices.

To gauge if that’s happened, let’s examine one of the best measures of where stocks stand on the continuum from excessively cheap to dangerously expensive. It’s the ratio of Total Market Cap (TMC), the value of all U.S. publicly traded companies, versus GDP, the value of all goods and services produced annually within our borders. Put simply, it shows the dollar size of the equity market as a share of the economy.

If the value of equities represents a far bigger than average share of national income, it probably means that epic earnings are devouring a much bigger share of national income than usual, leaving less for wages. That’s certainly the case today. In the past, the gravitational force of competition for both goods and labor has always restored balance by curbing excessive profits, and in most cases, driving down stock prices.

The TMC to GDP ratio is a favorite yardstick of Warren Buffett, who’s stated, that “it’s probably the best measure of where valuations stand at any given moment.” (We’ll refer to the measure as the “cap ratio.”)

Today, the value of all stocks to national income stands at 146.4. That’s the second highest reading in the past half-century, exceeded only by the 148.5 posted at the peak of the dot.com bubble on March 30, 2000. The cap ratio has averaged around 80 over the past decade, so it now exceeds that benchmark by 80%.

The cap ratio has varied widely over the past five decades, but typically returns to that reading of 80 after spiking well above, and plunging far below, that mean. By definition, over each period the ratio starts and ends at 80, earnings simply grow with GDP. (We’ll express GDP in “nominal,” not inflation-adjusted terms.) Still, it’s informative to study the careening course in between.

We’ll start at the 80 mark reached at the start of 1971. The cap ratio fell as low as 35 in the deep 1982 recession, and generally stayed below 50 from 1976 to 1986. It didn’t get back to 80 until the end of 1995, an interlude of 25 years. Over that period, the S&P 500 rose on average 7.3% a year, reflecting economic growth inflated by high inflation from the oil shock of the 1970s and early 1980s.

From that 80 reading at the end of 1995, through March 30 of 2000, the cap ratio went wild, jumping 86% to that record level of almost 150 at the height of the internet craze. Then, gravity took over, and by April of 2003, the “cap” had crashed back to 80. Over that 7-plus year period, the S&P 500 rose by a more or less normal 5.6%, half as fast as in the past half-decade, once again, tracking GDP.

From the 80 reading in early 2003, the ratio plunged to the low 50s during the 2009 financial crisis, and didn’t hit 80 again until October of 2011. Over those seven-and-a-half years, the S&P gained just 3.1% annually, as cratering home prices hobbled the economy.

Since returning to a “normal” level in late 2011, the cap ratio soared hockey-stick style, hitting the current 146.2 while suffering only minor blips along the way. Over those 7 years and 9 months, GDP rose 35%, from $15.6 trillion to $21.1 trillion. Total market cap leaped from $12.6 trillion to $3.014 trillion, or 148%. The S&P 500 delivered annual gains of 11%, while national income rose less than half as fast, by 4%.

Put simply, companies cut back on workers, held down wages, feasted from low interest rates on their debt, and otherwise benefited from a perfect calm for profits. And those trends totally trumped mediocre economic growth.

Two additional measures are flashing red. I often interviewed Milton Friedman, the legendary economist, before his death in 2006. Friedman told me that “in the long term, earnings cannot remain above their historical average as a share of national income.” The Nobel laureate also declared that although profit performance determines companies' values over lengthy periods, “markets in the short term are far from ‘efficient,’” meaning that equity prices can vary significantly from the enterprises' underlying value.

Today, according to the St. Louis Federal Reserve, corporate profits account for 9.2% of GDP. That’s one-third higher than the half-century average of 7%. Since profits normally “revert to the mean” a la Friedman, that gap is destined to shrink. Operating margins also look unsustainably high. According to S&P, the figure for the S&P 500 averaged 11.25% over the past four quarters, 25% above the average of 9% posted in the previous 30 quarters.

It’s conceivable that our economy really has changed, as the break-up-tech crowd in Congress argues, and that internet is enabling tech giants to operate as monopolies. That’'s the position adopted by a number of influential economists, including former Treasury Secretary Larry Summers. Another possibility: Because they’re so profitable, these players are prime targets by hungry startups that will eventually erode their profitability.

The best bet is that equity valuations return to a more normal share of national income. The past few years look like the kind of crazy uncoupling that happens every couple of decades, not a structural downshift from the world's most competitive market to a network of cartels.

The market hasn’t failed to rein in runaway profits yet, and it won’t fail this time.