Asymptotic properties of GPH estimators of the memory parameters of the fractionally integrated separable spatial ARMA FISSARMA models
Słowa kluczowe:Spatial processes, FISSARMA models, asymptotic properties, GPH estimators, long-memory parameters
In this article, we first extend Theorem 2 of Robinson from one dimension to two dimensions. Then the theoretical asymptotic properties of the means, variances, covariance and MSEs of the regression/ GPH GPH states for Geweke and Porter-Hudak’s estimators of the memory parameters of the FISSARMA model are established. We also performed simulations to study MSE and covariances for finite sample sizes. We found that through the simulation study the MSE values of the memory parameters tend to the theoretical MSE values as the sample size increases. It is also found that m1/2d^1 − d1 and m1/2d^2 − d2 are independent and identically distributed as N0; π2/24, when m = on4/5 and ln2 n = om.