Finding a suitable weight matrix in spatial GARCH models is a challenge when the actual locations are not known. Thus, we introduce an estimation procedure for spatial GARCH models when the locations are unknown. We suggest to use balance sheet data of companies as proxy for the spatial distance...

In this paper, we introduce the concept of fractional integration for spatial autoregressive models. We show that the range of the dependence can be spatially extended or diminished by introducing a further fractional integration parameter to spatial autoregressive moving average models (SARMA)....