A Note on the Size of the ADF Test with Additive Outliers and Fractional Errors. A Reappraisal about the (Non)Stationarity of the Latin-American Inflation Series

This note analyzes the empirical size of the augmented Dickey and Fuller (ADF) statistic proposedby Perron and Rodríguez (2003) when the errors are fractional. This ADF is based on a searching procedure for additive outliers based on first-differences of the data named td. Simulations show that empi...

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Detalles Bibliográficos
Autores: Rodríguez, Gabriel, Ramírez, Dionisio
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2014
País:Perú
Institución:Pontificia Universidad Católica del Perú
Repositorio:Revistas - Pontificia Universidad Católica del Perú
Idioma:español
OAI Identifier:oai:ojs.pkp.sfu.ca:article/10086
Acceso en línea:http://revistas.pucp.edu.pe/index.php/economia/article/view/10086
Access Level:acceso abierto
Palabra clave:additive outliers
ARFIMA erros
ADF Test
Outliers aditivos
errores ARFIMA
Test ADF
Descripción
Sumario:This note analyzes the empirical size of the augmented Dickey and Fuller (ADF) statistic proposedby Perron and Rodríguez (2003) when the errors are fractional. This ADF is based on a searching procedure for additive outliers based on first-differences of the data named td. Simulations show that empirical size of the ADF is not affected by fractional errors confirming the claim of Perron and Rodríguez (2003) that the procedure td is robust to departures of the unit root framework. In particular the results show low sensitivity of the size of the ADF statistic respect to the fractional parameter (d). However, as expected, when there is strong negative moving average autocorrelation or negative autoregressive autocorrelation, the ADF statistic is oversized. These difficulties are fixed when sample increases (from T = 100 to T = 200). Empirical application to eight quarterly Latin American inflation series is also provided showing the importance of taking into account dummy variables for the detected additive outliers.