统计研究 ›› 2023, Vol. 40 ›› Issue (4): 124-137.doi: 10.19343/j.cnki.11–1302/c.2023.04.010

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基于Knockoff的分位数回归变量选择方法及其投资组合决策应用

王小燕 张中艳   

  • 出版日期:2023-04-25 发布日期:2023-04-25

Variable Selection Method for Quantile Regression via Knockoff and Its Application in the Decision of Portfolio

Wang Xiaoyan & Zhang Zhongyan   

  • Online:2023-04-25 Published:2023-04-25

摘要: 在数据驱动时代,变量选择广泛应用于投资组合,如何从众多资产中挑选恰当的资产并进行配比,对稳定收益、控制风险非常关键。现有选择资产的方法未考虑到控制错误发现率(FDR),不利于作出稳健的投资决策。为此,本文在Lasso分位数回归下基于Knockoff方法控制FDR,并用于求解条件风险价值(CVaR)投资组合决策模型。其中,用Lasso惩罚实现变量选择,用Knockoff方法通过模仿解释变量的相关结构构造Knockoff变量,将变量选择的FDR控制在给定水平。模型在两步迭代算法下采用线性规划求解,模拟分析从不同的误差分布、变量分布和维度下多角度展开。结果显示,与已有模型相比,基于Knockoff的Lasso分位数回归模型能良好地控制FDR且呈现出最好的预测效果。最后基于上证50指数成分股进行实证分析,利用滚动建模技术进行投资组合决策分析,发现新模型在收益指标和风险指标上均具有一定优势。

关键词: 分位数回归, Knockoff, Lasso惩罚, 投资组合, CVaR

Abstract: In the current data-driven era, variable selection is commonly encountered in the field of investment portfolio. How to select assets from the numerous options available and allocate the investment proportion plays an important role in stabilizing return and controlling risk. The existing methods of asset selection do not take into account the control of false discovery rate (FDR), which is undoubtedly not conducive to making robust investment decisions. Therefore, a Lasso quantile regression based on Knockoff method is constructed to control FDR and used to solve the CVaR-based portfolio selection model. In the proposed model, Lasso penalty is implemented for variable selection. Knockoff method is designed to control the FDR of variable selection at the given level, which can mimic the correlation structure of the covariates. The model is solved by linear programming under a two-step iterative algorithm. The simulation study is conducted under various scenarios with different error distributions, covariates distributions, and dimensions. The results demonstrate that compared with the existing models, the proposed one can satisfactorily control FDR and presents the best prediction performance. Finally, an empirical study is conducted on SSE 50 stocks, and the rolling modeling technology is used to analyze the decision making of portfolio. It shows that the new model has advantages in return indexes and risk indexes.

Key words: Quantile Regression, Knockoff, Lasso Penalty, Portfolio, CVaR