This complementarity makes many parts of the developing world unsuitable for modern production, because key inputs are missing. Even within cities, poor areas are so disconnected and inadequately endowed that productivity is dismal.
互补性让许多发展中国家不适应现代生产，因为它们没有关键投入。即使在城市内部，较穷的地区也常常交通不便、禀赋不足，导致生产率低迷。结果，企业之间的效率存在巨大差异，它们可用来分配的收入亦然。