Robust Nonparametric Testing for Structural Changes in Multivariate Volatility via Multiple Quantiles
利用多分位数稳健检验多变量波动率的结构变化
We propose an omnibus nonparametric test for structural changes in the multivariate volatility matrix. The test aggregates bounded generalized quantile scores over a range of quantile levels and has a weighted leave-$q$-out $U$-statistic representation. Deleting nearby index pairs renders the centering effect induced by serial dependence asymptotically negligible. All quantities required for implementation, including the variance estimator used for standardization, are…