Document Type
Discussion Paper
Publication Date
4-1-2019
CFDP Number
2194R
CFDP Revision Date
March 1, 2020
CFDP Pages
35
Journal of Economic Literature (JEL) Code(s)
C12
Abstract
Commonly used tests to assess evidence for the absence of autocorrelation in a univariate time series or serial cross-correlation between time series rely on procedures whose validity holds for i.i.d. data. When the series are not i.i.d., the size of correlogram and cumulative Ljung-Box tests can be significantly distorted. This paper adapts standard correlogram and portmanteau tests to accommodate hidden dependence and non-stationarities involving heteroskedasticity, thereby uncoupling these tests from limiting assumptions that reduce their applicability in empirical work. To enhance the Ljung-Box test for non-i.i.d. data a new cumulative test is introduced. Asymptotic size of these tests is unaffected by hidden dependence and heteroskedasticity in the series. Related extensions are provided for testing cross-correlation at various lags in bivariate time series. Tests for the i.i.d. property of a time series are also developed. An extensive Monte Carlo study confirms good performance in both size and power for the new tests. Applications to real data reveal that standard tests frequently produce spurious evidence of serial correlation.
Recommended Citation
Dalla, Violetta; Giraitis, Liudas; and Phillips, Peter C.B., "Robust Tests for White Noise and Cross-Correlation" (2019). Cowles Foundation Discussion Papers. 57.
https://elischolar.library.yale.edu/cowles-discussion-paper-series/57
Comments
Supplement Materials, 54 pp