经济增长的收缩效应（之一）

Why the history of economic growth should be all about recessions

“THROUGHOUT history, poverty is the normal condition of man,” wrote Robert Heinlein, a science-fiction writer. Until the 18th century, global GDP per person was stuck between $725 and $1,100, around the same income level as the World Bank’s current poverty line of $1.90 a day. But global income levels per person have since accelerated, from around $1,100 in 1800 to $3,600 in 1950, and over $10,000 today.

为何经济增长史的一切端由应是衰退

“纵观历史，贫穷是人类社会的常态”，科幻作家罗伯特·海因莱因写道。直到18世纪，全球人均GDP一直停留在725至1100美金之间，这个收入水平大约与世界银行划定的贫困线持平，每天1.9美金。但从那时起，全球人均收入水平开始加速增长。从1800年的1100美金到1950年的3600美金，现在已经超过10000美金。

Economists have long tried to explain this sudden surge in output. Most theories have focused on the factors driving long-term economic growth such as the quantity and productivity of labour and capital. But a new paper* takes a different tack: faster growth is not due to bigger booms, but to less shrinking in recessions. Stephen Broadberry of Oxford University and John Wallis of the University of Maryland have taken data for 18 countries in Europe and the New World, some from as far back as the 13th century. To their surprise, they found that growth during years of economic expansion has fallen in the recent era—from 3.88% between 1820 and 1870 to 3.06% since 1950—even though average growth across all years in those two periods increased from 1.4% to 2.55%.

长久以来，经济学家试图解释这一产出激增。大多数理论都聚焦于驱动长期经济增长的因素，如劳动力数量和生产力以及资本。但是一篇新论文采取了不同的方法进行探究：增长加速并不是源于于繁荣期的更大发展，而是因为衰退期的收缩程度减弱。牛津大学的史蒂芬·布劳德伯利和马里兰大学的约翰·瓦利斯收集了欧洲和美洲的18个国家的数据，有些甚至追溯到13世纪。令他们惊讶的是，他们发现经济扩张年份的增长率在近期反而是下降的，从1820年至1870年的3.88%下降到1950年至今的3.06%，尽管这两个时期里所有年份的平均增长率从1.4%上升到了2.55%。