Seeds of growth? Agricultural productivity and the transitional dynamics of the Ramsey model
构建了一个两部门拉姆齐增长模型，研究农业生产力如何通过恩格尔定律影响资本积累速度和经济增长，发现低农业生产力会因高食品价格导致低储蓄率而成为增长瓶颈。
A two-sector Ramsey-type model of growth is developed to investigate the relationship between agricultural productivity and economy-wide growth. The framework takes into account the peculiarities of agriculture both in production ( reliance on a fixed natural resource base) and in consumption (life-sustaining role and low income elasticity of food demand). The transitional dynamics of the model establish that when preferences respect Engel's law, the level and growth rate of agricultural productivity influence the speed of capital accumulation. A calibration exercise shows that a small difference in agricultural productivity has drastic implications for the rate and pattern of growth of the economy. Hence, low agricultural productivity can form a bottleneck limiting growth, because high food prices result in a low saving rate.