Back Down to Earth A U.S. irony: Demand for tall buildings is in short supply —by Rick Hampson In this, the nation that invented the skyscraper, the tallest private building under construction is a pipsqueak (小人物) —just 30 stories. But overseas, the sky is the limit. In Kuala Lumpur, Malaysia, the twin Petronas Towers (双子塔) are rising to the heavens —they will be the world's tallest buildings, the first time that title has passed overseas. It probably will stay there. Ten years ago, the world's 10 tallest buildings were in three U.S. cities as recently as 1993 there were a half dozen proposals to build the next world champ here. But none was ever built, and today only 10 buildings over 20 stories are going up in the entire nation. By the turn of the century, six of the world's 10 tallest are expected to be in Southeast Asia. Has the American skyline topped out (封顶)? Is the signal achievement of America architecture drifting toward its twilight? 'The skyscraper is an artifact of an era when technology was frail and transportation inefficient, and people had to be together to do their jobs.' says David Birch, president of Cognetics, a Massachusetts marketing and economic research firm. 'The need for new ones now is nil. There is no logical reason to ever build another Empire State Building.' Last year, in fact, Bethlehem Steel closed the mill that made steel for the Empire State 65 years ago, citing the decline in high-rise construction. Now, America has so much vacant high-rise urban office space there probably will be no need for more at least until the turn of the century. About 43 percent of all U.S. office space was built in the last decade, as developers scrambled (争夺) to house the exploding demand. Boston, for example, increased its space from 21 million to 45 million square feet. But after the stock market crash of 1987, the economy slowed down. The national downtown office vacancy rate is 16.7 percent, —about 2.5 times higher than the real estate industry considers healthy. In Dallas the rate is 37 percent in Miami, 27 percent in Baltimore, 25 percent. In Seattle, neither the city's first skyscraper (the Smith Tower, 1914) nor its last (the AT&T Gateway Tower, 1990) are generating enough rent to service their debt. The 62-story Gateway, which cost ＄ 200 million, was on sale earlier this year for half that price. The building has never been more than half occupied, and the original investors lost their entire investment. Three years ago the German media conglomerate (集团公司) Bertelsmann snapped up (抢购) a new, never-been-occupied mid-Manhattan office tower for ＄119 million —a third of what it cost its bankrupt builder. Meanwhile, fundamental changes in the way we work are reducing the future demand for office in the clouds. Corporate America is getting leaner. An increasingly competitive world economy forces companies to cut costs, the biggest of which are office workers and the space they occupy. U.S. companies eliminated more than a half million positions last year alone there are fewer jobs in Manhattan now than 10 years ago. By one estimate, Fortune 500 layoffs have made 250 million square feet of office space available for sublease (转租), the equivalent of 250 Chrysler Buildings. The office is getting more suburban. Suburbs are popular places for off