Variance estimation for integrated population models
Variance estimation for integrated population models
复制标题
综合人口模型的方差估计
DOI：
10.1007/s10182-017-0304-5
复制
发表时间：
2017
期刊：
影响因子：
--
通讯作者：
B. Morgan
中科院分区：
文献类型：
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作者：
P. Besbeas;B. Morgan
状态空间模型在生态学中有着广泛的应用。然而，众所周知，在实践中，很难估计在这样的模型中发生的过程和观测方差。我们认为这个问题的综合人口模型，其中包括人口动态的状态空间模型。在某种程度上，综合人口模型的机制防止这个问题，但它仍然可以出现，并提供了两个例子，在每个观察方差估计为零。在一个扩展的案例研究的背景下，涉及英国灰鹭的数据，我们考虑的替代方法来处理这个问题时，它发生。特别是，我们认为惩罚的可能性，一种基于拟合样条和伪复制的方法，这是通过一个简单的引导程序进行的方法。对于本文的案例研究，它表明，当它发生时，零观测方差的估计是不重要的推断有关的模型参数的主要利益。这一意外发现得到了模拟研究的支持。
State-space models are widely used in ecology. However, it is well known that in practice it can be difficult to estimate both the process and observation variances that occur in such models. We consider this issue for integrated population models, which incorporate state-space models for population dynamics. To some extent, the mechanism of integrated population models protects against this problem, but it can still arise, and two illustrations are provided, in each of which the observation variance is estimated as zero. In the context of an extended case study involving data on British Grey herons, we consider alternative approaches for dealing with the problem when it occurs. In particular, we consider penalised likelihood, a method based on fitting splines and a method of pseudo-replication, which is undertaken via a simple bootstrap procedure. For the case study of the paper, it is shown that when it occurs, an estimate of zero observation variance is unimportant for inference relating to the model parameters of primary interest. This unexpected finding is supported by a simulation study.