Discontinuities in Robust Nonparametric Regression Discontinuities in Robust Nonparametric Regression with Α-mixing Dependence
Abstract
The main idea of the paper is to introduce a robust regression estimation method under an α-mixing dependence assumption, staying free of any para- metric model restrictions while also allowing for some sudden changes in the unknown regression function. The sudden changes in the model may correspond to discontinuity points (jumps) or higher order breaks (jumps in corresponding derivatives) as well.
We firstly derive some important statistical properties for local polynomial M-smoother estimates and we will propose a statistical test to decide whether some given point of interest is significantly important for a change to occur or not. As the asymptotic distribution of the test statistic depends on quantities which are left unknown we also introduce a bootstrap algorithm which can be used to mimic the target distribution of interest.
All necessary proofs are provided together with some experimental results from a simulation study and a real data example.