Wavelet semi-parametric inference for long memory in volatility in the presence of a trend |
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Authors: | Agnieszka Jach Piotr Kokoszka |
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Institution: | 1. Department of Finance and Statistics, Hanken School of Economics, Helsinki, Finlandagnieszka.jach@hanken.fi;3. Department of Statistics, Colorado State University, Fort Collins, CO, USA |
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Abstract: | Risk of investing in a financial asset is quantified by functionals of squared returns. Discrete time stochastic volatility (SV) models impose a convenient and practically relevant time series dependence structure on the log-squared returns. Different long-term risk characteristics are postulated by short-memory SV and long-memory SV models. It is therefore important to test which of these two alternatives is suitable for a specific asset. Most standard tests are confounded by deterministic trends. This paper introduces a new, wavelet-based, test of the null hypothesis of short versus long memory in volatility which is robust to deterministic trends. In finite samples, the test performs better than currently available tests which are based on the Fourier transform. |
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Keywords: | Deterministic trend long memory stochastic volatility wavelets |
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