inputoutputanalyses

Input-output analyses, also known as input-output analysis, are quantitative methods used to examine how the output of one economic sector serves as input to others, revealing interdependencies within an economy. Originating with Wassily Leontief in the 1930s, the approach provides a structured representation of production and consumption chains and remains a standard tool in macroeconomic planning, regional development, and environmental accounting.

The core is the input-output table, recording transactions between sectors. The direct requirements matrix A specifies the input from each sector needed to produce one unit of output in another. With final demand f, total production is x = (I - A)^{-1} f, the Leontief inverse. This yields multipliers that describe how final demand changes propagate through outputs, employment, and value added.

Applications include policy impact assessment, industry planning, and resilience studies for supply chains. Environmental input-output analysis links economic activity to environmental pressures, allowing estimates of energy use, emissions, or material throughput by sector. Regional IO models adapt the method to subnational geographies to study local economies.

Limitations include the assumptions of fixed technology and proportional input use, linearity, and no price dynamics or supply constraints. The method relies on aggregated data, which can obscure detail and dynamic adjustments. Data quality and timing affect reliability, and extensions address these issues through dynamic, stochastic, or hybrid approaches.

Related concepts include social accounting matrices, which expand the framework to households and government; energy and environmental IO analysis; and the Leontief paradox, a mismatch between theory and empirical results in some economies.