Economic Growth and Social Security

经济增长和社会保障

基本信息

批准号：
03630006
负责人：
NISHIMURA Kazuo
金额：
$ 1.09万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1991
资助国家：
日本
起止时间：
1991 至 1992
项目状态：
已结题

项目摘要

Exogenous fertility has usually been assumed in models of explaining the existence and effects of pay-as-you-go social security system. We assume that endogenous fertility is allowed in a two overlapping generations simple model with the young caring for the old. The social security level is modeled as a solution of an optimal allocation problem by the government. Social security benefit is assumed to be conditional on individual fertility.We have shown that, although the optimal allocation cannot be achieved in practice, individuals follow the social security level set by the government and reach a sustainable sub-optimal steady state. Furthermore, we have also shown that the sustainable steady state has higher utility than that of the steady state without a social security system.What is the future of pay-as-you-go public pensions in the face of declining population growth? One common view is pessimistic, in that the future young may choose to shed the burden of a larger and larger number of elderly. However in simple model, which incorporates interactions between endogenous population growth and economic variables,public pensions are themselves a contributing factor to the decline in population growth. In the model, such pensions are sustainable and improve steady state welfare.These results also provide importanr messages to many developing countries where transfers to the old still occur within families as the major old-age support and over-population is a common problem. Our results imply that moving towards a social security system would be welfare-improving, and would lead to declining fertility. Thus the over-population problem can be solved even with improved welfare on an individual level.

通常在解释付费社会保障系统的存在和影响的模型中假定外源性生育能力。我们假设在两个重叠的世代中允许内源性生育能力，而年轻的照顾旧模型。政府将社会保障水平建立为解决最佳分配问题的解决方案。假定社会保障福利是基于个人生育能力的条件。我们已经表明，尽管在实践中无法实现最佳分配，但个人遵循政府设定的社会保障水平，并达到可持续的次优稳定状态。此外，我们还表明，在没有社会保障系统的情况下，可持续的稳态效用比稳态更高。面对人口增长的下降，付费公共养老金的未来是什么？一种常见的观点是悲观的，因为未来的年轻人可能会选择减轻越来越多的老年人的负担。但是，在简单的模型中，该模型结合了内源人口增长与经济变量之间的相互作用，公共养老金本身就是导致人口增长下降的一个因素。在模型中，这种养老金是可持续的，并改善了稳态福利。这些结果还向许多发展中国家提供了重要的信息，在这些发展中国家，由于主要的老年支持和人口过多是一个普遍的问题，向旧的人转移到了旧的家庭中。我们的结果表明，朝着社会保障制度迈进将是福利改善，并导致生育能力下降。因此，即使在个人层面上有改善的福利，也可以解决人口过多的问题。