The study examines whether the factor of intensity competition by firms was reason for recent price increase in building materials markets Russia. author develops a estimation model to explain role market power ready-mixed concrete and crushed stone regional markets’ prices during 2021 applying “difference difference” approach. analysis shows that it wasn’t responsible considered markets. Thus,...

The basic assumption in the traditional inventory model is that all outputs are perfect items. However, this assumption is too simplistic in the most real-life situations due to a natural phenomenon in a production process. From this it is deduced that the system produces non-perfects items which can be classified into four groups of perfect, imperfect, reworkable defective and non-reworkable d...

The effect of imperfect production processes on lot sizing decisions received a lot of attention in the literature. These efforts have been almost confined to single stage production systems. The issue of imperfect production processes has not been adequately addressed in the context of multistage production/inventory systems. In this paper, we propose a two-stage production inventory model tha...

This paper considers a modified empirical likelihood and uses it to estimate models with imperfect moment restrictions. Consistency, local normality and asymptotic optimality of the new estimator only require the local identifiability and the linear-quadratic representation. In imperfect situations, classical sandwich algorithms give bias estimations while the new estimator preserves its asympt...