Hostname: page-component-cd9895bd7-gxg78 Total loading time: 0 Render date: 2024-12-29T00:20:21.600Z Has data issue: false hasContentIssue false

ADMISSIBLE AND NONADMISSIBLE TESTS IN UNIT-ROOT-LIKE SITUATIONS

Published online by Cambridge University Press:  06 September 2007

Werner Ploberger
Affiliation:
Washington University in St. Louis

Abstract

This paper investigates the asymptotic behavior of tests in situations where the likelihood is locally asymptotically quadratic. Necessary and sufficient conditions are given for a test to be admissible. Even without these restrictive parametric assumptions, it is shown that certain common procedures—such as the augmented Dickey–Fuller test in cases where no deterministic trend is present or standard tests for restrictions on cointegrating relationships—are asymptotically inadmissible. These results confirm the existence of tests that dominate these classical tests for all parameters.I express my gratitude to the editors, H. Lütkepohl and especially Peter C.B. Phillips, for their help, which enormously exceeded the usual amount of support. Also I thank the referees for their helpful comments. Their contribution greatly improved the paper. All remaining errors are mine.

Type
Research Article
Copyright
© 2008 Cambridge University Press

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Aït-Sahalia, Y. (1999) Maximum Likelihood Estimation of Discretely Sampled Diffusions: A Closed-Form Approach. Discussion paper, Princeton University.
Ahn, S.K. & G.C. Reinsel (1990) Estimation for partially nonstationary multivariate autoregressive models. Journal of the American Statistical Association 85, 813823.Google Scholar
Chang, Y. & J. Park (2002) On the asymptotics of ADF tests for unit roots. Econometric Reviews 21, 432477.Google Scholar
Davidson, J. (1998) A Wald test of restrictions on the cointegrating space based on Johansen's estimator. Economics Letters 59, 183187.Google Scholar
Dickey, D.A. & W.A. Fuller (1979) Distribution of estimators for autoregressive time series with a unit root. Journal of the American Statistical Association 74, 427431.Google Scholar
Dickey, D.A. & W.A. Fuller (1981) Likelihood ratio tests for autoregressive series with a unit root. Econometrica 64, 10571072.Google Scholar
Elliot, G., T.J. Rothenberg, & J.H. Stock (1996) Efficient tests for an autoregressive unit root. Econometrica 64, 813836.Google Scholar
Hamilton, J.D. (1994) Time Series Analysis. Princeton University Press.
Jeganathan, P. (1991) Some aspects of asymptotic theory with application to time series models. Econometric Theory 7, 269306.Google Scholar
Jeganathan, P. (1995) Some aspects of asymptotic theory with applications to time series models. Econometric Theory 11, 818867.Google Scholar
Johansen, S. (1988) Statistical analysis of cointegrating vectors. Journal of Economics Dynamics and Control 12, 231254.Google Scholar
Johansen, S. (1991) Cointegration and hypothesis testing of cointegration vectors in Gaussian vector autoregressive models. Econometrica 59, 15511580.Google Scholar
Le Cam, L. & G.L. Yang (1990) Asymptotics in Statistics: Some Basic Concepts. Springer-Verlag.
Müller, U. & G. Elliot (2001) Tests for Unit Root and the Initial Observation. Discussion paper, University of St. Gallen.
Park, J. & P.C.B. Phillips (2001) Nonlinear regressions with integrated time series. Econometrics 69, 117161.Google Scholar
Phillips, P.C.B (1996) Econometric model determination. Econometrica 64, 763812.Google Scholar
Phillips, P.C.B. & B.E. Hansen (1990) Statistical inference in instrumental variables regression with I(1) processes. Review of Economic Studies 57, 99125.Google Scholar
Phillips, P.C.B. & S. Ouliaris (1990) Asymptotic properties of residual based tests for cointegration. Econometrica 58, 165193.Google Scholar
Phillips, P.C.B. & W. Ploberger (1996) An asymptotic theory of Bayesian inference for time series. Econometrica 64, 381412.Google Scholar
Phillips, P.C.B. & Z. Xiao (1998) A Primer on Unit Root Testing. Cowles Foundation Discussion paper, Yale University.
Ploberger, W. (2004) A complete class of tests when the likelihood is locally asymptotically quadratic. Journal of Econometrics 118, 6794.Google Scholar
Ploberger, W. & P.C.B. Phillips (2003) Empirical limits for time series models. Econometrica 71, 627674.Google Scholar
Rudin, W. (1974) Real and Complex Analysis, 2nd ed. Reprinted by Tata-McGraw-Hill.
Said, S.E. & D.A. Dickey (1984) Testing for unit roots in ARMA models of unknown order. Biometrika 71, 599607.Google Scholar
Saikkonen, P. (1991) Asymptotically efficient estimation of cointegrating regressions. Econometric Theory 7, 121.Google Scholar
Schervish, M.J. (1995) Theory of Statistics. Springer-Verlag.
Stock, J.H. (1995) Unit roots, structural breaks and trends. In R.F. Engle & D. McFadden (eds.), Handbook of Econometrics, vol. 4, pp. 27392841. North-Holland.
Stock, J.H. & M. Watson (1993) A simple estimator of cointegrating vectors in higher order integrated systems. Econometrica 51, 783820.Google Scholar
Strasser, H. (1985) Mathematical Theory of Statistics. De Gruyter.