This paper proposes empirical likelihood based inference methods for causal effects identified from regression discontinuity designs. We consider both the sharp and fuzzy regression discontinuity designs and treat the regression functions as nonparametric. The proposed inference procedures do...

The CUSUMSQ test of homoskedasticity is shown in the autoregression model to be consistent against a broad range of nonstationary volatility specification recently studied in the literature. The limit distribution is derived, and numerical examples are presented to illustrate the theoretical...

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....