Toward an Understanding of Economic Growth in Africa: A Reinterpretation of the Lewis Model
扩展了刘易斯模型，加入中间部门，强调农业和非农业部门生产率增长及贸易条件对结构转型的重要性，并指出外国融资的公共投资会导致实际汇率升值，抑制开放现代部门扩张，部分解释了卢旺达等非洲国家的增长模式。
We develop a model economy that has many of the features of Lewis (1954) but that also includes an in-between sector as described by Lewis (1979). Our model underscores the importance of the following determinants of structural change: (i) productivity growth in the agricultural sector; (ii) productivity growth in the nonagricultural sector and; (iii) the terms of trade. Public investment enhances productivity growth in all sectors but when it is financed by foreign inflows, it also causes a real exchange rate appreciation leading to a contraction in the open modern sector. These results provide a partial explanation for recent patterns of growth in Rwanda and elsewhere in Africa where the nontradables or what we call the in-between sector has expanded more rapidly than the tradable sector. Our results also highlight the dilemma faced by poor countries in dire need of public investment with a very limited tax base.