Hyperbolic Discounting is Rational: Valuing the Far Future with Uncertain Discount Rates
Hyperbolic Discounting is Rational: Valuing the Far Future with Uncertain Discount Rates
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双曲线贴现是理性的：用不确定的贴现率来评估遥远的未来
DOI：
10.2139/ssrn.1448811
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发表时间：
2009
期刊：
影响因子：
--
通讯作者：
R. Townsend
中科院分区：
文献类型：
--
作者：
A. Karaivanov;R. Townsend
传统经济学假设代理人使用指数折现函数对现在和未来进行估值。相比之下，动物和人类的实验表明，智能体更适合被描述为双曲折现者，其折现函数在大时间内以幂律的形式衰减得慢得多。这通常被认为是时间不一致或不合理的。我们证明了当代理人不能确定自己未来的一期折现率时，双曲折现可以变成理性折现，指数折现可以变成非理性折现。这对环境经济学具有重要意义，因为它意味着对遥远未来的影响要大得多。
Conventional economics supposes that agents value the present vs. the future using an exponential discounting function. In contrast, experiments with animals and humans suggest that agents are better described as hyperbolic discounters, whose discount function decays much more slowly at large times, as a power law. This is generally regarded as being time inconsistent or irrational. We show that when agents cannot be sure of their own future one-period discount rates, then hyperbolic discounting can become rational and exponential discounting irrational. This has important implications for environmental economics, as it implies a much larger weight for the far future.