The evolution of cost-productivity and efficiency among US credit unions

► We examine the evolution of efficiency, productivity, etc. among US credit unions. ► We adapt the order-α quantile estimator to handle quasi-fixed outputs. ► Average cost-productivity declined among US credit unions between 1989 and 2006. ► Attainable minimum cost increased for small credit unions. ► All but the largest credit unions became less scale efficient over time.