Fractile Graphical Analysis (FGA) was proposed by Prasanta Chandra Mahalanobis in 1961 as a method for comparing two distributions at two different points (of time or space) controlling for the rank of a covariate through fractile groups. We use bootstrap techniques to formalize the heuristic...

This paper derives unbalanced versions of the tests statistics for ¯rst order serial correlation and random individual e®ects summarized in Sosa Escudero and Bera (2001), and updates their xttest1 routine. The derived tests statistics should be useful for applied researchers faced with the...