In this note, we recollect some formulas and facts about linear mixed models in relation to Cohen’s effect size measure f2. It is shown how an estimate of the variance-covariance matrix for the estimated fixed effects parameter vector may serve to compute f2in the presence of random effects....

Financial return distributions often exhibit central asymmetry and heavy-tailed extremes, challenging standard parametric models. We propose a novel composite distribution integrating a skew-normal center with skew-t tails, partitioning the support into three regions with smooth junctions. The...

Typically, the inefficiency term in stochastic frontier models is assumed to be positively skewed; however, efficiency scores are biased if this assumption is violated. This paper considers the case in which negative skewness is also allowed in the model. The paper discusses estimation of a...