Generative Predictive Distributions for Time Series
时间序列的生成式预测分布
Jordi Llorens-Terrazas, Mika Meitz
AI总结 提出基于生成式表示的灵活框架,用于建模非线性多变量时间序列的预测分布,通过条件生成对抗网络估计,并建立弱时间依赖下的统计一致性。
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我们提出了一个灵活的框架,用于建模非线性、可能多变量时间序列的预测分布。我们的方法基于测度论概率中的一个民间结果,在适当的生成式表示中表达一般的预测分布。这种表示为预测分布提供了直接的基于模拟的近似,从而能够直接计算条件均值和方差的预测、扇形图、风险价值、预期亏损、联合尾部风险以及其他感兴趣的量。我们使用条件生成对抗网络的一个版本来估计这种生成式表示,并提供了弱时间依赖下估计的形式化统计分析。具体来说,估计被表述为一个特定的极小极大问题,并且我们建立了其近似解在豪斯多夫距离下的一致性。通过应用于股票收益、已实现方差和已实现协方差的例子,说明了该方法的实证相关性。所提出的方法在计算上也是可管理的,在我们的应用中,在标准笔记本电脑上估计大约需要一分钟。
We propose a flexible framework for modeling the predictive distributions of nonlinear, possibly multivariate time series. Our approach expresses a general predictive distribution in an appropriate generative representation that is based on a folklore result from measure theoretic probability. This representation provides a direct simulation-based approximation to the predictive distribution, enabling straightforward computation of forecasts for the conditional mean and variance, fan charts, value at risk, expected shortfall, joint tail risks, and other quantities of interest. We estimate this generative representation using a version of conditional generative adversarial networks and provide a formal statistical analysis of estimation under weak temporal dependence. Specifically, estimation is expressed as a particular minimax problem and we establish consistency of its approximate solutions in Hausdorff distance. The empirical relevance of the approach is illustrated using applications to equity returns, realized variance, and realized covariances. The proposed method is also computationally manageable, with estimation in our applications taking approximately one minute on a standard laptop.