The paper introduces the class of seasonal specific structural time series models, according to which each season follows specific dynamics, but is also tied to the others by a common random effect. Seasonal specific models are dynamic variance components models that account for some kind of...

This paper addresses the issue of convergence of per-capita GDP of the 20 Italian regions. The paper first focuses on the notion of σ-convergence and proposes a new hierarchical clustering algorithm, grouping regions according to the presence of a monotonically decreasing trend in entropy. Then...

This note shows the equivalence of the dummy variable approach and the skipping approach for the treatment of missing observations in state space models. The equivalence holds when the coefficient of the dummy variable is considered as a diffuse rather than a fixed effect. The equivalence...