Virginia Postrel visits the World Fair in Shanghai, where she considers the conventional wisdom "that Americans lost their fondness for world's fairs because we became pessimistic and disillusioned about progress."
If so, the naïve enthusiasms on display in Shanghai suggest that the future belongs to the Chinese. But the real story is more complicated. In part, world's fairs were simply victims of the prosperity they prophesied. The more affluent, well-traveled, and media-saturated the audience, the harder it is to impress. World's fairs are designed for people from homogeneous cultures who are still impressed by electricity and foreigners. In 2010, that means the Chinese.
A world's fair is a chance to see the cultures and people of other lands—to "smell, touch, and taste far-off places," promised a pavilion at the 1964 World's Fair in New York. A Shanghai writer observes that for older locals and migrants from the countryside, "the Expo is—and may well remain—the closest that they will ever get to seeing the world."
Deeper than that, there's a shift in political attitudes:
General Motors's Futurama exhibit at the 1939 New York World's Fair turned this idea into a seductive and memorable experience, as visitors soared over a miniature world of superhighways and high-rise, self-contained cities. "No matter what I had heard about the Futurama," recalls the protagonist of E.L. Doctorow's World's Fair, "nothing compared with seeing it for myself: all the small moving parts, all the lights and shadows, the animation, as if I were looking at the largest most complicated toy ever made!…It was a toy that any child in the world would want to own. You could play with it forever." The Futurama was enticing because visitors never considered what it might feel like to be someone else's toy.
That vision did give America interstate highways and a trip to the moon. But it also sparked a backlash. In the 1960s, the New Left and the Goldwater Right, hippies and hackers, personal liberation movements and historic preservationists all rebelled against the tyranny of expertise. Within a few years, Robert Moses, the New York infrastructure and planning czar who ran the 1964 World's Fair, had gone from city-building hero to neighborhood-wrecking villain. (In Shanghai, the government displaced some 18,000 households to clear the land for the Expo site, Moses-style; the official account portrays the relocations as a move to a "sweet and fresh" new life, while others disagree.) With its mix of do-it-yourself technophilia, hippie experimentation, and environmental consciousness, the best-selling Whole Earth Catalog captured the Zeitgeist and won the 1972 National Book Award.
Twentieth-century world's fairs had encouraged visitors to equate progress and technological optimism with the Galbraithian vision of stable, heavily bureaucratic, industrial quasi-monopolies—the corporate version of nation states—working with government to determine the future. All the rage in the first half of the 20th century, this technocratic theory of progress became not only less popular but much less believable in the second half.