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arXiv 2210.01099stat.MEcs.LG
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模型误差及其估计,特别适用于损失准备金

Model error and its estimation, with particular application to loss reserving

University of New South Wales(新南威尔士大学);Taylor Fry(泰勒弗莱公司)

G Taylor, G McGuire

摘要:

本文主要研究预测误差,特别是损失准备金。这通常被认为是由三个组成部分,即参数,过程和模型误差。前两个组成部分及其估计是很好理解的,但模型误差就不那么容易理解了。模型误差本身被认为是两部分:一部分是能够估计从过去的数据(内部模型误差),另一部分是不能(外部模型误差)。这里的注意力集中在内部模型误差上。这个误差分量的估计接近贝叶斯模型平均,使用贝叶斯解释的LASSO。这用于生成一组可接受的模型,每个模型具有其先验概率和观测数据的似然性。模型集上的后验,以数据、结果和模型误差的估计(包含在损失准备金中)为条件,作为根据该后验的损失准备金的方差。材料进入后部支撑的模型群体可能比预期的更薄,并且LASSO的自举用于增加体积。这也提供了参数误差估计的好处。事实证明,参数和模型误差的估计是纠缠在一起的,它们的分离至少是困难的,甚至可能没有意义。这些问题都在讨论中。大多数的讨论适用于预测一般,但数值说明的概念给出了有关的保险数据和保险损失准备金的问题。

英文摘要:

This paper is concerned with forecast error, particularly in relation to loss reserving. This is generally regarded as consisting of three components, namely parameter, process and model errors. The first two of these components, and their estimation, are well understood, but less so model error. Model error itself is considered in two parts: one part that is capable of estimation from past data (internal model error), and another part that is not (external model error). Attention is focused here on internal model error. Estimation of this error component is approached by means of Bayesian model averaging, using the Bayesian interpretation of the LASSO. This is used to generate a set of admissible models, each with its prior probability and the likelihood of observed data. A posterior on the model set, conditional on the data, results, and an estimate of model error (contained in a loss reserve) is obtained as the variance of the loss reserve according to this posterior. The population of models entering materially into the support of the posterior may turn out to be thinner than desired, and bootstrapping of the LASSO is used to gain bulk. This provides the bonus of an estimate of parameter error also. It turns out that the estimates of parameter and model errors are entangled, and dissociation of them is at least difficult, and possibly not even meaningful. These matters are discussed. The majority of the discussion applies to forecasting generally, but numerical illustration of the concepts is given in relation to insurance data and the problem of insurance loss reserving.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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