Nonstationarity of the volatility process reflects low-frequency volatility changes of an economic time series, and its theoretical and empirical relevance has been widely recognized. We investigate how it affects CUSUM-related tests for structural change in regression coefficients....

Detecting structural changes in volatility is important for understanding volatility dynamics and stylized facts observed for financial returns such as volatility persistence. We propose modified CUSUM and LM tests that are built on a robust estimator of the long run variance of squared series....