Reexamination of the Serendipity Theorem from the Stability Viewpoint
Reexamination of the Serendipity Theorem from the Stability Viewpoint
复制标题
从稳定性角度重新审视偶然性定理
DOI：
10.1017/dem.2018.21
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发表时间：
2019
影响因子：
1.3
通讯作者：
Akihisa Shibata
中科院分区：
文献类型：
--
作者：
Akira Momota;Tomoya Sakagami;Akihisa Shibata
本文从稳定性的角度重新审视了Samuelson(1975)的奇遇定理，证明了对于Cobb-Douglas偏好和CES技术，稳定的最黄金规则寿命状态依赖于参数值。在某些情况下，尽管人口增长率使稳定状态的福利最大化，但由于稳定状态是不稳定的，意外发现定理并不成立。通过数值模拟，我们还考察了更一般的CES偏好和CES技术的情况，并讨论了我们的结果的现实相关性。我们给出了结果的政策含义，即在某些情况下，效用最高的稳态是不稳定的，因此，旨在通过操纵人口增长率来实现社会最优的政策可能会导致更糟糕的结果。
This paper reexamines the Serendipity Theorem of Samuelson (1975) from the stability viewpoint, and shows that, for the Cobb–Douglas preference and CES technology, the most-golden golden-rule lifetime state being stable depends on parameter values. In some situations, the Serendipity Theorem fails to hold despite the fact that steady-state welfare is maximized at the population growth rate, since the steady state is unstable. Through numerical simulations, a more general case of CES preference and CES technology is also examined, and we discuss the realistic relevance of our results. We present the policy implication of our result, that is, in some cases, the steady state with the highest utility is unstable, and thus a policy that aims to achieve the social optima by manipulating the population growth rate may lead to worse outcomes.