Detection of additive outliers in seasonal time series
The detection and location of additive outliers in integrated variables has attracted much attention recently because such outliers tend to affect unit root inference among other things. Most of these procedures have been developed for non-seasonal processes. However, the presence of seasonality in the form of seasonally varying means and variances affect the properties of outlier detection procedures, and hence appropriate adjustments of existing methods are needed for seasonal data. In this paper we suggest modifications of tests proposed by Shin et al. (1996) and Perron and Rodriguez (2003) to deal with data sampled at a seasonal frequency and the size and power properties are discussed. We also show that the presence of periodic heteroscedasticity will inflate the size of the tests and hence will tend to identify an excessive number of outliers. A modified Perron-Rodriguez test which allows periodically varying variances is suggested and it is shown to have excellent properties in terms of both power and size.
|Date of creation:||14 Sep 2009|
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- Pierre Perron & Serena Ng, 1996.
"Useful Modifications to some Unit Root Tests with Dependent Errors and their Local Asymptotic Properties,"
Review of Economic Studies,
Oxford University Press, vol. 63(3), pages 435-463.
- Perron, P. & Ng, S., 1994. "Useful Modifications to Some Unit Root Tests with Dependent Errors and Their Local Asymptotic Properties," Cahiers de recherche 9427, Centre interuniversitaire de recherche en économie quantitative, CIREQ.
- Perron, P. & Ng, S., 1994. "Useful Modifications to Some Unit Root Tests with Dependent Errors and Their Local Asymptotic Properties," Cahiers de recherche 9427, Universite de Montreal, Departement de sciences economiques.
- Niels Haldrup & Andreu Sansó, 2006.
"A Note on the Vogelsang Test for Additive Outliers,"
Economics Working Papers
2006-01, Department of Economics and Business Economics, Aarhus University.
- Haldrup, Niels & Sansó, Andreu, 2008. "A note on the Vogelsang test for additive outliers," Statistics & Probability Letters, Elsevier, vol. 78(3), pages 296-300, February.
- Burridge, P. & Taylor, A.M.R., 1999.
"On Regression-Based Tests for Seasonal Unit Roots in the Presence of Periodic Heteroscedasticity,"
99-10, Department of Economics, University of Birmingham.
- Burridge, Peter & Taylor, A. M. Robert, 2001. "On regression-based tests for seasonal unit roots in the presence of periodic heteroscedasticity," Journal of Econometrics, Elsevier, vol. 104(1), pages 91-117, August.
- Niels Haldrup & Antonio Montanés & Andreu Sanso, .
"Measurement Errors and Outliers in Seasonal Unit Root Testing,"
Economics Working Papers
2000-8, Department of Economics and Business Economics, Aarhus University.
- Haldrup, Niels & Montanes, Antonio & Sanso, Andreu, 2005. "Measurement errors and outliers in seasonal unit root testing," Journal of Econometrics, Elsevier, vol. 127(1), pages 103-128, July.
- Haldrup, Niels Prof. & Montanes, Antonio & SansÃ³, Andreu, 2000. "Measurement Errors and Outliers in Seasonal Unit Root Testing," University of California at San Diego, Economics Working Paper Series qt0gw7q9hk, Department of Economics, UC San Diego.
- Shin, Dong Wan & Sarkar, Sahadeb & Lee, Jong Hyup, 1996. "Unit root tests for time series with outliers," Statistics & Probability Letters, Elsevier, vol. 30(3), pages 189-197, October.
- Franses, Philip Hans & Haldrup, Niels, 1994. "The Effects of Additive Outliers on Tests for Unit Roots and Cointegration," Journal of Business & Economic Statistics, American Statistical Association, vol. 12(4), pages 471-78, October.
- Perron, P. & Rodriguez, G., 2000.
"Seraching for Additive Outliers in Nonstationary Time Series,"
0005e, University of Ottawa, Department of Economics.
- Pierre Perron & Gabriel RodrÌguez, 2003. "Searching For Additive Outliers In Nonstationary Time Series," Journal of Time Series Analysis, Wiley Blackwell, vol. 24(2), pages 193-220, 03.
- Franses, Philip Hans, 1996. "Periodicity and Stochastic Trends in Economic Time Series," OUP Catalogue, Oxford University Press, number 9780198774549, December.
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