The process of economic development is characterized by substantial reallocations of resources across sectors. In this paper, we construct a multi-sector model in which there are barriers to the movement of labor from low-productivity traditional agriculture to modern sectors. With the barrier in place, we show that improvements in productivity in modern sectors (including agriculture) or reductions in transportation costs may lead to a rise in agricultural employment and through terms-oftrade effects may harm subsistence farmers if the traditional subsistence sector is larger than a critical level. This suggests that policy advice based on the earlier literature needs to be revised. Reducing barriers to mobility (through reductions in the cost of skill acquisition and institutional changes) and improving the productivity of subsistence farmers needs to precede policies designed to increase the productivity of modern sectors or decrease transportation costs.
This paper examines past African growth experience and attempts to simulate future ones. In addition to more commonly used determinants of total factor productivity, a measure of the effect of labor reallocation and an index of economic diversification are constructed and included as factors for long-term growth. A simple model is constructed for the purpose of simulating growth scenarios up to the year 2020 for Burkina Faso, Côte d'Ivoire, Ghana, Mali, Tanzania, and Uganda. Even if one makes relatively optimistic assumptions, Africa is not likely to reach "Asian tiger" levels of growth. The results also suggest that growth will depend, to a large extent, on educational investments and productivity gains in agriculture.