JOINT ASYMPTOTIC DISTRIBUTIONS OF SAMPLE AUTOCORRELATIONS FOR TIME SERIES OF MARTINGALE DIFFERENCES

  • Hwang, S.Y. (Department of Statistics, Sookmyung Women's University) ;
  • Baek, J.S. (Department of Statistics, Sookmyung Women's University) ;
  • Lim, K.E. (Department of Statistics, Sookmyung Women's University)
  • Published : 2006.12.31

Abstract

It is well known fact for the iid data that the limiting standard errors of sample autocorrelations are all unity for all time lags and they are asymptotically independent for different lags (Brockwell and Davis, 1991). It is also usual practice in time series modeling that this fact continues to be valid for white noise series which is a sequence of uncorrelated random variables. This paper contradicts this usual practice for white noise. We consider a sequence of martingale differences which belongs to white noise time series and derive exact joint asymptotic distributions of sample autocorrelations. Some implications of the result are illustrated for conditionally heteroscedastic time series.

Keywords

References

  1. BILLINGSLEY, P. (1961). 'The Lindeberg-Levy theorem for martingales', Proceedings of the American Mathematical Association, 12, 788-792
  2. BOLLERSLEV, T. (1986). 'Generalized autoregressive conditional heteroscedasticity', Journal of Econometrics, 31, 307-327 https://doi.org/10.1016/0304-4076(86)90063-1
  3. Box, G. E. P. AND PIERCE, D. A. (1970). 'Distribution of residual autocorrelation in autoregressive-integrated moving average time series models', Journal of the American Statistical Association, 65, 1509-1526 https://doi.org/10.2307/2284333
  4. BROCKWELL, P. J. AND DAVIS, R. A. (1991). Time Series: Theory and Methods, 2nd ed., Springer-Verlag, New York
  5. ENGLE, R. F. (1982). 'Autoregressive conditional heteroskedasticity with estimates of the variance of United Kingdom inflation', Econometrica, 50, 987-1008 https://doi.org/10.2307/1912773
  6. FULLER, W. A. (1996). Introduction to Statistical Time Series, 2nd ed., John Wiley & Sons, New York
  7. HWANG, S. Y., BASAWA, I. V. AND REEVES, J. (1994). 'The asymptotic distributions of residual autocorrelations and related tests of fit for a class of nonlinear time series models' , Statistica Sinica, 4, 107-125
  8. SERFLING, R. J. (1980). Approximation Theorems of Mathematical Statistics, John Wiley & Sons, New York