Threshold Externalities in Economic Development
扩展了Diamond模型，引入人力资本积累的社会规模报酬递增，从而产生多个局部稳定的稳态，解释了相似技术经济体可能不收敛的现象。
Standard one-sector growth models often have the counterfactual implication that economies with access to similar technologies will converge to a common balanced growth path. We propose an elaboration of the Diamond model that permits multiple, locally stable stationary states. This multiplicity is due to increasing social returns to scale in the accumulation of human capital.