期刊名称:International Journal of Statistics and Probability
印刷版ISSN:1927-7032
电子版ISSN:1927-7040
出版年度:2017
卷号:6
期号:4
页码:31
DOI:10.5539/ijsp.v6n4p31
出版社:Canadian Center of Science and Education
摘要:Simultaneous spatial autoregressive model is widely used for spatial data analysis, observed at a set of grid points in a space. However a problem, not so well known, is that there exists no unique model unlike time series AR model for given autocovariances or spectral density. We show that such a non-identifiability of the model implies existence of multiple maximum likelihood estimates under Gaussianity and causes non-estimability of parameters and the singularity of Fisher information matrix. Several types of necessary and sufficient conditions for the singularity are given.