TY JOUR TI A quantitative model for assessing the economic effect of introducing an intelligent product substitution subsystem in online grocery retail KW e-grocery; online retail; out-of-stock; product substitutions; acceptance rate; economic effect; retail digitalization; assortment management; investment project appraisal JO JOURNAL OF MONETARY ECONOMICS AND MANAGEMENT AU Guseynov, D.N. AU Petrov, V.I. AU Filatova, A.. PY 2026 IS PB ITBO University