economic development
Shrink wrap
Why the history of economic growth should be all about recessions
经济发展
收缩效应
为何经济增长史的关键在于衰退
“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.
“纵观历史，贫穷是人们的常态。”科幻作家罗伯特·海因莱因(Robert Heinlein)写道。直到18世纪，全球人均GDP一直停留在725美元至1100美元之间，这个收入水平大致相当于目前世界银行划定的贫困线：每天1.9美元。但从那时起，全球人均收入水平开始加速增长，从1800年的1100美元左右上升至1950年的3600美元，现在已超过10,000美元。
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%.
经济学家长期以来一直试图解释何以出现这一产出的激增。大多数理论都聚焦于驱动长期经济增长的因素，如劳动力的数量和生产率，以及资本。但一篇新论文*采用了不同的方法加以探究，认为增长加快并非缘于繁荣期更加蓬勃发展，而是因为衰退期的收缩程度减弱。牛津大学的斯蒂芬·布劳德伯利(Stephen Broadberry)和马里兰大学的约翰·沃里斯(John Wallis) 收集了来自欧洲和美洲共18个国家早至13世纪的数据。他们惊奇地发现，经济扩张期的增长率在近期反而是下降的：在1820至1870年间，经济扩张年份的增长率为3.88%，而从1950年至今，这一数字为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%。
Instead, shorter and shallower slumps led to rising long-term growth. Output fell in a third of years between 1820 and 1870 but in only 12% of those since 1950. The rate of decline per recession year has fallen too, from 3% to 1.2%.
相反，是衰退期缩短及其程度的减轻带来了更快的长期增长。1820年至1870年间，三分之一的年份出现产出下降，但自1950年以来，产出下降的年头仅占12%，每一个衰退年份的下降幅度也从3%减至1.2%。
So why have these “growth reversals” decreased in length and depth? In another paper** Messrs Broadberry and Wallis find that conventional explanations—such as demographic change or a sectoral shift from volatile agriculture to the more stable services sector—do not fully explain the shift.
这些“增长逆转期”为何在时间和程度上出现下降?在另一篇论文**中，布劳德伯利和沃里斯发现，常规推论(如人口结构变化或经济部门转移，即从波动较大的农业转向更稳定的服务业)并不能完全解释这种变化。
More important is the rise of the rule of law, enabling disputes to be settled by impartial courts. Before the modern era, elites would fight between themselves for the spoils of growth and send the economy back to square one through wars, corruption and the like. Respect for courts to resolve disputes prevents this from happening. With populist politicians challenging the authority of judges once again across the world, that is food for thought.
更重要的是法治的兴起，使人们可以通过公正的法庭解决争议。现代之前，精英之间为夺取经济增长成果而争斗不休，因此产生的战争、贪腐等更是会令经济崩塌归零。尊重法院解决纠纷则可以防止这种情况发生。随着当今全球各地民粹主义政客再次挑战法官的权威，上述观点值得我们深思。
* “Growing, Shrinking and Long Run Economic Performance: Historical Perspectives on Economic Development” by S. Broadberry and J. Wallis
** “Shrink Theory: The Nature of Long Run and Short Run Economic Performance”
*《增长、收缩和长期经济表现：从历史角度看经济发展》，斯蒂芬·布劳德伯利及约翰·沃里斯著
**《收缩理论：长期及短期经济表现的本质》
