问答题 Americans' entrepreneurial self-esteem is now embodied by Apple, Google, Facebook and Amazon. These are indeed fabulously innovative companies with world-class business models. Yet one wonders if they are increasingly the exception, not the rule, and if the passing of Mr. Jobs is simply the most prominent example of a broader decline in American entrepreneurship. According to JPMorgan, employment at start-up companies regularly grew 1.2m per quarter in the late 1990s. That has fallen to 700,000 since the current recovery began. Entrepreneurship and innovation, of course, are not the same thing. Yet even if American innovation is fundamentally sound, there remains the more unsettling problem of how narrowly its fruits are shared. If you want to know why the Senate is on the verge of passing a bill punishing China for its trade practices, look no further than this fact: Apple, Google, Facebook and Amazon collectively employ just 113,000 people, a third of GM's payroll in 1980. Naturally, as Adam Smith pointed out long ago, the sole purpose of production is consumption, so one should not scoff at the benefits these companies create for Americans in their other role as consumers rather than workers. And in truth, technological advancement has probably done far more than trade to hollow out the middle class and widen inequality. Slapping China with punitive tariffs is more likely to trigger a trade war than restore millions of middle-class jobs.