AbstractThis paper is based on the use of Flegg's location quotients (FLQ) and proposes a novel procedure for the estimation of the unknown parameter δ in regions with and without input–output frame availability. Applied to data for the Korean regions for the year 2015, firstly the determination of the optimal δ is addressed by solving a general optimization problem and, secondly, a regression equation is proposed to estimate the value of δ from the explanatory variables of interregional road freight transport (IRFT) and imports from the rest of the world (IROW). The results obtained show a lower bias in regard to the true values of the regional inputs coefficients in relation to other methods based on location quotients.