America is in the midst of an extraordinary startup boom

Although America has a deserved reputation as a country at the cutting-edge of innovation, fuelled by entrepreneurial vim, in recent years some economists have worried that this reputation no longer holds true. Startups have formed a smaller and smaller portion of the business landscape: in 1982 some 38% of American firms were less than five years old; by 2018, 29% were that young. The share of Americans working for startups likewise fell. Silicon Valley sizzled with high-tech wizardry, but its giant companies hoarded the best researchers, leading to a slower spread of new ideas throughout the country. Researchers, including at the Federal Reserve, pointed to this decline in dynamism as a cause of weaker productivity growth.