Asymptotic Behavior of the Variance of the Best Linear Unbiased Estimator for the Mean of a Discrete-time Singular Stationary Process

Journal of Contemporary Mathematical Analysis - Tập 54 - Trang 371-380 - 2019
N. M. Babayan1, M. S. Ginovyan2,3
1Russian-Armenian University, Yerevan, Armenia
2Institute of Mathematics, Yerevan, Armenia
3Boston University, Boston, USA

Tóm tắt

It is known that for a wide class of discrete-time stationary processes possessing spectral densities f, the variance σ2(f) of the best linear unbiased estimator for the mean depends asymptotically only on the behavior of the spectral density f near the origin, and behaves hyperbolically as n → ∞. In this paper, we obtain necessary as well as sufficient conditions for exponential rate of decrease of σ2(f) as n → ∞. In particular, we show that a necessary condition for σ2(f) to decrease to zero exponentially is that the spectral density f vanishes on a set of positive measure in any vicinity of zero, and if f vanishes only at the origin, then it is impossible to obtain exponential decay of σ2(f), no mater how high the order of the zero of f at the origin.

Tài liệu tham khảo

R. K. Adenstedt, “On large-sample estimation for the mean of a stationary random sequence”, Ann. Stat., 2, 1095–1107, 1974. R. K. Adenstedt, B. Eisenberg, “Linear estimation of regression coefficients”, Quart. Appl. Math., 32(3), 317–327, 1974. N. M. Babayan, “On the asymptotic behavior of prediction error”, J. of Soviet Mathematics, 27(6), 3170–3181, 1984. N. M. Babayan, “On asymptotic behavior of the prediction error in the singular case”, Theory Probab. Appl., 29(1), 147–150, 1985. J. Beran, “Recent developments in location estimation and regression for long-memory processes”, In “New directions in time series analysis, part II” (D. Brillingeret al. eds.) 46, 1–10, 1993. J. Beran, H. Künsch, “Location estimates for processes with long range dependence”, Research Report No. 40, Seminar für Statistik, Eidenössische Technische Hochschule, Zürich, 1985. J. Beran, Y. Feng, S. Ghosh, R. Kulik, Long-Memory Processes: Probabilistic Properties and Statistical Methods (Springer, Berlin, 2013). Ya. L. Geronimus, “On certain asymptotic properties of polynomials”, Mat. Sb., 23(65) (1), 77–88, 1948. G. M. Goluzin, Geometric Theory of Functions of a Complex Variable (Amer. Math. Soc., Providence, 1969). U. Grenander, “Stochastic processes and statistical inference”, Ark. Mat., 1(17), 195–277, 1950. U. Grenander, “On Toeplitz forms and stationary processes”, Ark. Mat., 1(37), 555–571, 1952. U. Grenander, “On the estimation of regression coefficients in the case of an autocorrelated disturbance”, Ann. Math. Stat., 25, 252–272, 1954. U. Grenander, M. Rosenblatt, Statistical Analysis of Stationary Time Series (Wiley, New York, 1957). U. Grenander, G. Szegö, Toeplitz Forms and Their Applications (University of California Press, Berkeley, 1958). S. Mazurkievicz, “Un theoreme sur les polynomes”, Ann. Soc. Polon. Math., 18, 113–118, 1945. E. M. Nikishin, V. N. Sorokin, Rational Approximations and Orthogonality (American Mathematical Society, Providence, 1991). M. Rosenblatt “Some Purely Deterministic Processes”, J. of Math. and Mech., 6(6), 801–810, 1957. A. Samarov, M.S. Taqqu, “On the efficiency of the sample mean in long-memory noise”, J. Time Series Analysis, 9, 191–200, 1988. R.A. Vitale, “An asymptotically efficient estimate in time series analysis”, Quart. Appl. Math., 30, 421–440, 1973. Y. Yajima, “On estimation of a regression model with long-memory stationary errors”, Ann. Stat., 16, 791–807, 1988.