Robustness of Power Properties of Non-linearity Tests

The paper examines the robustness of the size and power properties of the standard non-linearity tests under different conditions such as moment failure and asymmetry of innovations. Our results reveal the following. First, there seems not to be a direct link between moment condition failure and the power variation of non-linearity tests. Second, the power of the tests is very sensitive to asymmetry of innovations compared to moment condition failure. Third, although we evaluate 9 non-linear time series models using 8 standard non-linearity tests, some non-linear models remain completely undetected.