经济增长的复利效应极其巨大：经济体若按年均约1%增长，两代人后规模甚至翻不了一番；若按年均7%增长，规模则大约扩大30倍。1960年时韩国与加纳收入相近，如今韩国已进入高收入生活，而典型加纳人仍然每天生活费不足4美元，这表明仅仅几个百分点的长期增长差异就会深刻改变寿命、儿童存活率、教育与生活水平。
增长研究的重心曾从国家层面转向家庭与村庄层面，如今又转向企业层面，因为企业规模与扩张决定了总产出。在许多发展中国家，典型企业只有1名劳动者即业主本人；即便雇人，多数企业员工也不足10人，而2010年代的研究指出，印度和印度尼西亚员工少于10人的企业占比“几乎与100%无法区分”，相比之下，美国制造企业平均雇员超过20人。
关键问题不仅是企业小，而且是高生产率企业无法做大：在美国，厂龄超过40年的工厂雇员人数是厂龄不足5年工厂的7倍，在墨西哥仅为2倍，在印度增长更弱。跨100多个国家的数据表明，贫穷国家中最高生产率企业并不会扩大就业；若消除错配，Hsieh和Klenow估计印度生产率最高可提高60%，而管理改进也带来持续收益，例如对6000多家、17个国家企业的研究显示管理质量与生产率强相关，小企业培训平均使利润提高约10%、销售提高约5%，印度纺织企业在近10年后工人生产率仍高约35%，意大利企业从美国学习后的收益至少持续15年。
The arithmetic of compounding makes growth differences enormous: an economy growing at about 1% a year will not even double over two generations, while one growing at 7% will expand roughly 30-fold. South Korea and Ghana had similar incomes in 1960, but today typical Ghanaians still live on less than $4 a day, showing how a few percentage points of long-run growth can transform survival, longevity, schooling, and living standards.
Growth research first compared whole countries, then shifted toward households and villages, and is now returning to firms because firm size and expansion shape aggregate output. In much of the developing world, the typical firm has just 1 worker, the owner; even among employers, most firms have fewer than 10 workers, and 2010s research said the share with under 10 workers in India and Indonesia was “almost indistinguishable from 100%,” whereas the average American manufacturer employs more than 20 people.
The central problem is not only that firms are small, but that productive ones fail to grow: in America, factories older than 40 years employ 7 times as many workers as factories younger than 5 years, versus only 2 times in Mexico, and even less in India. Evidence from more than 100 countries shows that top firms in poorer economies do not expand employment as they do in richer ones; removing distortions could raise India’s productivity by as much as 60%, while management improvements also produce durable gains, with surveys of more than 6,000 firms across 17 countries linking management quality to productivity, small-business training raising profits by about 10% and sales by roughly 5%, Indian textile consulting lifting worker productivity by about 35% nearly a decade later, and Italian Marshall Plan trainees seeing gains last at least 15 years.
Source: To understand why countries grow, look at their firms
Subtitle: The third way in development economics
Dateline: 3月 05, 2026 04:15 上午