????上周五下午公布的致伯克希爾?哈撒韋公司（Berkshire Hathaway）股東年度公開信中，巴菲特說，他仍然相信美國股市“會好起來”。他說，他在第二次世界大戰最凄涼的時候購買了人生中的第一只股票，因此，即使目前形勢看起來沒有那么好，投資者最終還是會好起來。

????但我們還是將這封信與去年的信對比一下吧。在去年的公開信中，巴菲特用了三頁半的文字（超過1,900字）詳細解釋了他認為股票比黃金和債券投資價值高得多的理由。（參見《沃倫?巴菲特：股票為什么跑贏黃金和債券》）。他還說，他看好美國住房市場。

????而這一次他只用了四段話談股票投資。即便在這么小的篇幅內，巴菲特還說，投資者應該預計到周期性的打擊，而且他還列出了兩項可能預示著一場風波提前來臨的統計數據。

????巴菲特指出，道瓊斯工業平均指數在20世紀的漲幅達到了驚人的17320%，盡管期間經歷了“四次代價巨大的戰爭、大蕭條和許多次經濟衰退。”這里存在一個問題：巴菲特說，在幾乎同一時期，人均國內生產總值（GDP）增幅約為500%，要少得多。

????巴菲特以前就用過這種針對經濟和股市估值的比較。2001年，他為《財富》雜志撰文并介紹了這個指標。（參見《沃倫?巴菲特論股市》）。那時，美國股市已經小幅脫離了互聯網泡沫行情的高點。但巴菲特當時說，還不能買入股票。原因是：盡管股價下滑，但當時美國股市整體估值占美國GDP的133%【巴菲特用的是國民生產總值（GNP），因為它可以追溯到80年前，但對于近期數據，GDP也好用。】

????那么，現在美國股市的表現如何？不妨先猜一下。結果是：占GDP的133%。

????這個指標曾經在1999年達到高點190%。因此，我們還遠遠沒有達到恐慌水平，但是，這并不意味著美國股市目前是安全的。事實上，它的安全性很低。早在2001年，巴菲特曾說過，在股市估值占GDP比降至70%至80%的區間內買進股票的投資者應該表現不錯。這意味著美國股市要暴跌43%才會到達巴菲特建議買進的水平。

????即便如此，巴菲特似乎并不擔心。在他自己的投資組合中，巴菲特在過去一年中增持了沃爾瑪公司（Wal-Mart）和富國銀行（Wells Fargo）。這兩家公司的股票只有在經濟和市場其余部分也上行的時候才會上漲。

????很難說這是因為巴菲特認為股票廉價，還是因為其他投資選擇更糟糕。 “不參加這場（股市）游戲的風險要遠大于參與其中的風險，”巴菲特在信中寫道。“所有明天向來都是不明朗的。”（財富中文網）

????譯者：默默

????In his annual letter to Berkshire Hathaway (BRKA) shareholders, released Friday afternoon, Buffett says he still believes U.S. stocks will "do well." He notes that he made his first stock purchase during the bleakest part of World War II, so even if things look not so great right now, you should end up doing fine as well.

????But compare that to last year's letter. Buffett devoted three and a half pages - over 1,900 words - to a detailed explanation of why he thought stocks were a much better investment than say gold or bonds. (See Warren Buffett: Why stocks beat gold and bonds.) He also said he wasbullish on U.S. housing.

????This time around he devotes four paragraphs to the case for stocks. And even in that small space, Buffett says that investors should expect periodic setbacks, and he includes two statistics that could signal one may be coming up sooner rather than later.

????Buffett points out that the Dow Jones Industrial Average rose "a staggering" 17,320% in the 20th century -- despite "four costly wars, a Great Depression and numerous recessions." Here's the problem: During nearly the same period, Buffett says GDP per capita rose much less about 500%.

????Buffett has used this comparison of the economy to stock market valuations before. He featured the metric in a story he wrote for Fortune back in 2001. (See Warren Buffett on the stock market) By that time, stocks had already fallen a bit from their dot-com infused highs. But they still weren't a buy, Buffett said at the time. Despite their fall, stocks collectively were trading at a value of 133% of the gross national product of the U.S. (Buffett used GNP because it goes back 80 years, but for recent history using GDP works just fine.)

????So where are stocks trading today? You guessed it. 133% of GDP.

????The metric hit a high of 190% back in 1999. So we are a little ways from panic territory, but that doesn't mean the market is a safe place to be right now. Far from it. Back in 2001, Buffett said investors who buy when the relationship of stock values to the economy falls in the 70% to 80% range should do well. That means stocks would have to plummet 43% before we are back in Buffett buy territory.

????Even so, Buffett doesn't appear to be worried. In his own portfolio, Buffett in the past year has added to his stakes in Wal-Mart (WMT) and Wells Fargo (WFC), two companies that are likely to go up only if the economy and the rest of the market does as well.

????It's hard to tell if that's because Buffett believes stocks are cheap, or just because he believes the other investing options are worse. "The risks of being out of the [stock market] game are huge compared to the risks of being in it," writes Buffett in the letter. "Every tomorrow has been uncertain."