Testing for Unit Roots in Autoregressions with Multiple Level Shifts

Testing for Unit Roots in Autoregressions with Multiple Level Shifts PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
The asymptotic distributions of Augmented-Dickey-Fuller (ADF) unit root tests for autoregressive processes with a unit or near-unit root are discussed in the presence of multiple stochastic level shifts of large size occurring independently in time. The distributions depend on a Brownian motion and a Poisson-type jump process. Due to the latter, tests based on standard critical values experience power losses increasing rapidly with the number and the magnitude of the shifts. A new approach to unit root testing is suggested which requires no knowledge of either the location or the number of level shifts, and which dispenses with the assumption of independent shift occurrence. It is proposed to remove possible shifts from a time series by weighting its increments according to how likely it is, with respect to an ad hoc postulated distribution, a shift to have occurred in each period. If the number of level shifts is bounded in probability, the limiting distributions of the proposed test statistics coincide with those of ADF statistics under standard conditions. A Monte Carlo experiment shows that, despite their generality, the new tests perform well in finite samples.

Testing for Unit Roots in Autoregressions with Multiple Level Shifts

Testing for Unit Roots in Autoregressions with Multiple Level Shifts PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
The asymptotic distributions of Augmented-Dickey-Fuller (ADF) unit root tests for autoregressive processes with a unit or near-unit root are discussed in the presence of multiple stochastic level shifts of large size occurring independently in time. The distributions depend on a Brownian motion and a Poisson-type jump process. Due to the latter, tests based on standard critical values experience power losses increasing rapidly with the number and the magnitude of the shifts. A new approach to unit root testing is suggested which requires no knowledge of either the location or the number of level shifts, and which dispenses with the assumption of independent shift occurrence. It is proposed to remove possible shifts from a time series by weighting its increments according to how likely it is, with respect to an ad hoc postulated distribution, a shift to have occurred in each period. If the number of level shifts is bounded in probability, the limiting distributions of the proposed test statistics coincide with those of ADF statistics under standard conditions. A Monte Carlo experiment shows that, despite their generality, the new tests perform well in finite samples.

Unit Root Tests in Time Series Volume 2

Unit Root Tests in Time Series Volume 2 PDF Author: K. Patterson
Publisher: Springer
ISBN: 1137003316
Category : Business & Economics
Languages : en
Pages : 586

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Book Description
Testing for a Unit Root is now an essential part of time series analysis but the literature on the topic is so large that knowing where to start is difficult even for the specialist. This book provides a way into the techniques of unit root testing, explaining the pitfalls and nonstandard cases, using practical examples and simulation analysis.

Almost All About Unit Roots

Almost All About Unit Roots PDF Author: In Choi
Publisher: Cambridge University Press
ISBN: 1107097339
Category : Business & Economics
Languages : en
Pages : 301

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Book Description
Many economic theories depend on the presence or absence of a unit root for their validity, making familiarity with unit roots extremely important to econometric and statistical theory. This book introduces the literature on unit roots in a comprehensive manner to empirical and theoretical researchers in economics and other areas.

Comparison of Unit Root Tests for Time Series with Level Shifts

Comparison of Unit Root Tests for Time Series with Level Shifts PDF Author: Markku Lanne
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
Unit root tests are considered for time series which have a level shift at a known point in time. The shift can have a very general nonlinear form, and additional deterministic mean and trend terms are allowed for. Prior to the tests, the deterministic parts and other nuisance parameters of the data generation process are estimated in a first step. Then, the series are adjusted for these terms and unit root tests of the Dickey-Fuller type are applied to the adjusted series. The properties of previously suggested tests of this sort are analysed and modifications are proposed which take into account estimation errors in the nuisance parameters. An important result is that estimation under the null hypothesis is preferable to estimation under local alternatives. This contrasts with results obtained by other authors for time series without level shifts.

Unit Roots, Cointegration, and Structural Change

Unit Roots, Cointegration, and Structural Change PDF Author: G. S. Maddala
Publisher: Cambridge University Press
ISBN: 9780521587822
Category : Business & Economics
Languages : en
Pages : 528

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Book Description
A comprehensive review of unit roots, cointegration and structural change from a best-selling author.

Testing for a Unit Root in Variables with a Double Change in the Mean

Testing for a Unit Root in Variables with a Double Change in the Mean PDF Author: Jesús Clemente
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
In this paper, we obtain a statistic that is useful for the analysis of the integration order of a variable which exhibits two changes in its mean. Our work begins by showing that the most commonly used unit root tests behave asymptotically in a correct manner for double changing mean variables. However, their use is not advisable in finite samples; rather, is better to design a new statistic which takes into account the presence of the two level shifts. We calculate the asymptotic distribution of this new statistic and tabulate it for several sample sizes using Monte Carlo methods. This new statistic allows us to show that the USA and UK real interest rates can be considered as stationary variables with a double shift in their mean.

Introduction to Statistical Time Series

Introduction to Statistical Time Series PDF Author: Wayne A. Fuller
Publisher: John Wiley & Sons
ISBN: 0470317752
Category : Mathematics
Languages : en
Pages : 734

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Book Description
The subject of time series is of considerable interest, especiallyamong researchers in econometrics, engineering, and the naturalsciences. As part of the prestigious Wiley Series in Probabilityand Statistics, this book provides a lucid introduction to thefield and, in this new Second Edition, covers the importantadvances of recent years, including nonstationary models, nonlinearestimation, multivariate models, state space representations, andempirical model identification. New sections have also been addedon the Wold decomposition, partial autocorrelation, long memoryprocesses, and the Kalman filter. Major topics include: * Moving average and autoregressive processes * Introduction to Fourier analysis * Spectral theory and filtering * Large sample theory * Estimation of the mean and autocorrelations * Estimation of the spectrum * Parameter estimation * Regression, trend, and seasonality * Unit root and explosive time series To accommodate a wide variety of readers, review material,especially on elementary results in Fourier analysis, large samplestatistics, and difference equations, has been included.

Unit Roots and Structural Breaks

Unit Roots and Structural Breaks PDF Author: Pierre Perron
Publisher:
ISBN: 9783038428121
Category :
Languages : en
Pages :

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Book Description
Unit Roots and Structural Breaks.

Empirical Vector Autoregressive Modeling

Empirical Vector Autoregressive Modeling PDF Author: Marius Ooms
Publisher: Springer Science & Business Media
ISBN: 3642487920
Category : Business & Economics
Languages : en
Pages : 397

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Book Description
1. 1 Integrating results The empirical study of macroeconomic time series is interesting. It is also difficult and not immediately rewarding. Many statistical and economic issues are involved. The main problems is that these issues are so interrelated that it does not seem sensible to address them one at a time. As soon as one sets about the making of a model of macroeconomic time series one has to choose which problems one will try to tackle oneself and which problems one will leave unresolved or to be solved by others. From a theoretic point of view it can be fruitful to concentrate oneself on only one problem. If one follows this strategy in empirical application one runs a serious risk of making a seemingly interesting model, that is just a corollary of some important mistake in the handling of other problems. Two well known examples of statistical artifacts are the finding of Kuznets "pseudo-waves" of about 20 years in economic activity (Sargent (1979, p. 248)) and the "spurious regression" of macroeconomic time series described in Granger and Newbold (1986, §6. 4). The easiest way to get away with possible mistakes is to admit they may be there in the first place, but that time constraints and unfamiliarity with the solution do not allow the researcher to do something about them. This can be a viable argument.

Unit Roots, Level Shifts and Purchasing Power Parity

Unit Roots, Level Shifts and Purchasing Power Parity PDF Author: Antonio Montañes
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
In this paper we analyse the unit root hypothesis when the variable being studied exhibits two changes in its mean. To that end, we design a new statistic which tests for the joint hypothesis that the autoregressive parameter is 1 and that the parameters associated with the structural breaks that appear under the alternative hypothesis are 0. The use of this statistic shows that the real exchange rate of the US dollar with the currencies that are closely linked to the German Mark are stationary around two changes in the mean for the 1974: 1-1995: 4 sample.