A simple test for constant correlation matrix

09/19/2018

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by   Malay Bhattacharyya, et al.

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We propose a simple procedure to test for changes in correlation matrix at an unknown point in time. This test requires constant expectations and variances, but only mild assumptions on the serial dependence structure. We test for a breakdown in correlation structure using eigenvalue decomposition. We derive the asymptotic distribution under the null hypothesis and apply the test to stock returns. We compute the power of our test and compare it with the power of other known tests.