I arrived in the Washington bureau of The Wall Street Journal shortly after the stock-market crash of 1987. Except for a stint as Berlin bureau chief, I've been tracking the economy from that perch ever since.

Looking back over that quarter century, four surprises stand out:

That the American middle class hasn't done better

In a 1998 book, my colleague Bob Davis and I argued the U.S. was on the cusp of an era of broadly shared prosperity that would boost the middle class. We were wrong. We correctly saw the potential of information technology, but we expected the gap between winners and losers to narrow. It didn't.

Output of goods and services per person has grown by about 45% since 1987. That's substantial, but the percentage increase is only half the 90% increase of the preceding 26 years (1961-1987).

For folks in the middle, the past quarter century doesn't look so good. The cash income of the median family, the one at the statistical middle, barely kept up with inflation. Add in health insurance and other noncash benefits, and it has risen significantly more. But here's an arresting fact: Adjusted for inflation, the typical man who worked full-time made less in 2012 ($49,398) than his analog did in 1987 ($50,166). Because more women were educated and landed better-paying jobs, they did better: Median earnings rose 16%.

Where did the money go? Disproportionately to the best off, the best educated, the two-professional couples, the winners on Wall Street and in Silicon Valley. Technology and globalization favored the best-educated. The rise of finance paid some handsomely. Earnings of those at the top of almost every field rose faster than at the middle.

Different measures show differences in degree, but the trend is clear: The latest Census data show the share of pretax income going to the top 5% of families rose from 15.7% in 1962 to 17.2% in 1987 to 21.3% in 2012. Higher tax rates on the well-off and benefits aimed at the bottom dampen the trend, but that wealth redistribution hasn't offset inequality-widening market forces.

That China has done so well

China is an economic miracle. Lawrence Summers, the former U.S. Treasury secretary, puts it this way: When the U.S. was growing at its fastest, it doubled living standards about every 30 years. China has been doubling living standards roughly each decade for the past 30 years--and it has done so without following Washington's playbook for development.

In 1987, the big Asian economic threat was Japan. China had demonstrated impressive growth, but few then foresaw how long that growth spurt would last. 'China's super-rapid growth has already lasted three times longer than a typical episode [in world history] and is the longest ever,' Mr. Summers said recently.

He doubts China can keep this up, and he's probably right. But that doesn't detract from its remarkable success: The World Bank estimates that since initiating market reforms in 1978, China has lifted more than 500 million out of poverty.

That 9/11 didn't have a longer-lasting harmful economic impact

When the planes hit the World Trade Center and Pentagon on Sept. 11, 2001, we all knew that the U.S. would never be the same--and it isn't. The attacks led to the wars in Afghanistan and Iraq, to government surveillance that wouldn't have been tolerated previously and to all those airport screeners.

At the time, it looked like this added security would be sand in the gears of the economy. It has been a costly hassle, and it's hard to tell if it was worth it: No one knows how many terrorists have been discouraged by airport and office-building checkpoints.

But looking at the whole economy, it's hard to see Sept. 11 as a damper on productivity. Output per hour of work has risen 2.1% in the 12 years since the attacks; it rose 2.2% a year in 12 preceding years. Other factors proved far more important than the productivity drain from stepped-up security.

That the U.S. was so vulnerable to a financial shock

One of few things on which most economists and policy makers agreed in 1987 was that the U.S. would never be threatened by anything resembling the Great Depression. We were too smart to let that happen again. The 1987 stock-market crash reinforced that; the lasting economic harm was minor. So did the Asian financial crisis of 1997 and the bursting tech-stock bubble in 2000.

The Federal Reserve became convinced--and convinced a lot of others--that mopping up after a financial crisis was better than trying to prevent one.

That was wrong. The 2007-09 financial crisis shattered the illusion that the U.S. had a well-regulated or well-managed financial system or that it could absorb a financial hit. The entire financial system, it turned out, was a house of cards resting on a faulty assumption that house prices across the country would never fall.

Great Depression 2.0 was avoided, thanks to aggressive government policy, but the economy suffered the worst recession since then. At 7%, unemployment today remains at levels once seen only in recessions. And until the system is tested again, no one can be certain that changes in regulation and business practices are sufficient to avoid a repeat.

1987年股市崩盘之后不久我就来到了《华尔街日报》的华盛顿分社。从此之后，除了在柏林分社担任过一任社长之外，我一直在这个位置追踪全球经济。

回顾过去的这四分之一世纪，有四个意外特别值得一提。

美国中产阶级的总体状况并没有改善

在1998年出版的一本书中，针对美国即将迎来各阶层同享繁荣的时代而且中产阶级将由此得到提振的观点，我与同事戴维斯(Bob Davis)进行了一番争辩。我们都错了。在信息技术的潜力这方面，我们的看法是对的，但我们曾认为，赢家和输家之间的差距将缩小，但这并没有发生。

商品和服务的人均产出自1987年以来已经上涨了45%。这以涨幅已经不小，但相比之下，这只是之前26年（1961年-1987年）90%的涨幅的一半。

对于中产阶级来说，过去的这四分之一世纪看上去没那么好。中位家庭（从统计角度来说位于中间的家庭）的现金收入勉强赶上了通胀的步伐。在医疗保险和其他非现金福利方面，涨幅则大得多。但一个令人不安的事实是：经通胀调整后，典型的全职工作者2012年的收入（49,398美元）相比1987年（50,166美元）有所减少。因为有更多女性接受教育，并获得了收入更高的工作，女性的总体状况得到了改善：中位收入上升了16%。

钱都去哪儿了呢？大得超过比例的一部分进到了这些家庭的口袋：最富有、受教育程度最高、夫妻双方都是专业人士以及华尔街和硅谷的赢家。技术和全球化最青睐那些受教育程度最高的人。金融业的崛起让一些人大赚了一笔。几乎所有领域的顶尖者收入的涨幅都高于中间人士。

采用不同的测量方法得到的差异程度有所不同，但趋势相当明朗：最新的人口普查局数据表明，收入最高的5%家庭获得的税前收入的比例从1962年的15.7%上升到1987年的17.2%，2012年为21.3%。高收入人群的税率较高，再加上底层人士的福利提高，令这一趋势有所缓和，但财富再分配手段并没有抵消令不平等趋势扩大的的市场力量。

中国发展太快了

Reuters浙江一轧钢厂的工人中国是个经济奇迹。美国前财长萨默斯(Lawrence Summers)是这样说的：美国在发展最快的时候，每30年令国民的生活水准提高一倍，而在过去的30年里，中国差不多每10年将国民的生活水准提高一倍，而且中国这一成就是在没有沿袭美国发展模式的情况下取得的。

1987年，亚洲最大的经济威胁是日本。中国已经取得了令人瞩目的增长，但当时几乎没有人能预见这种喷射式增长能持续多久。萨默斯不久前说，中国超高速增长期已经是世界上典型增长期的三倍长，也是有史以来最长的。

他对中国能否维持这一高速增长态势持怀疑态度，他或许是对的。但这并不能让中国令世人侧目的成功为之减损：据世界银行(World Bank)估计，自1978年实行改革开放以来，中国已经让5亿人口脱离了贫困。

911恐怖袭击没有给经济造成更持久的不利影响

Associated Press曼哈顿世贸中心塔楼顶部浓烟滚滚。2001年9月11日几架飞机撞上世界贸易中心和五角大楼时，我们都知道美国将永远不再是原来的美国了，事实也确实如此。911恐怖袭击引发了阿富汗和伊拉克的战争，引发了以前人们不会容忍的政府监控，引发了机场配备各种安检筛查设备。

当时，安保的加强似乎将成为经济中的害群之马。这样做不仅麻烦多多，而且代价不菲，很难说加强安保是否值得：没有人知道有多少恐怖分子被机场和办公楼的安检点吓退。

但看看整个经济，很难说911恐怖袭击对生产率造成了损害。911恐怖袭击以来的这12年，每小时生产率每年上升2.1%；在那之前的12年，每年上升2.2%。事实证明，相比生产率的小幅下滑，升级的安保对其他方面影响更大。

美国在金融风暴面前竟如此脆弱

Associated Press一名男子离开雷曼兄弟总部。1987年，大部分经济学家和决策者达成的为数不多的几项共识之一是，美国将永远不会再受到类似于大萧条这种事情的威胁。当时他们认为，我们很聪明，不会让这样的事再次发生。1987年的股市崩盘更强化了这一认知；持续的经济损害很小。1997年亚洲金融危机也是如此，2000年的科技股泡沫破裂也是如此。

美联储(Federal Reserve)相信并让其他很多人相信，发生金融危机后收拾残局比试图阻止危机的发生更好。

这种看法是错误的。2007年-2009年的金融危机粉碎了这样一种错误观念：美国拥有一个监管良好、管理良好的金融体系，或美国可以消化金融打击。事实证明，整个金融体系是一座建立在全美房价永远不会跌的错误假设之上的纸牌屋。

由于政府的激进政策，我们避免了大萧条2.0版，但经济此后经历了最严重的衰退。目前失业率高达7%，仍处于曾经只有在衰退中才会看到的水平。此外，在金融体系再次受到考验之前，没有人能够肯定监管实践和商业实践的改变足以避免重蹈覆辙。