The document discusses the input-output analysis model, developed by Wassily Leontief in 1951, which analyzes the inter-industry relationships in an economy to maintain equilibrium between supply and demand. It outlines the model's main features, assumptions, and the construction of an input-output table, detailing the processing and payments sectors. Additionally, it highlights the model's uses in economic planning and forecasting, particularly in developed economies with significant industrial interdependencies.