Economic relationships between industries that arise from transactions of goods, services, intermediate inputs, or outputs and that create interdependencies in production, demand, or technological change across sectors.

Principle

Shocks, demand changes, or technological shifts in one industry propagate to others along transactional links; the strength and direction of propagation depend on the composition and intensity of input‑output relationships and the potential for substitution or diversification.

Demonstration

Illustrative scenario → An abrupt demand contraction for passenger vehicles (Situation) reduces orders for steel and specific electronic components (Recognition/Action by firms to cut production). Suppliers to the affected industries reduce output and may lay off workers, spreading the initial shock across manufacturing and related services (Consequence).

Misapplication

Concluding that all observed co‑movement across sectors implies direct interindustry linkage. The error is failing to distinguish common exposure (e.g., to macro demand) from substantive transactional dependence transmitted via supplier‑buyer relationships.

Consequence

Interindustry linkages determine how localized shocks become systemic, shape comparative advantage, and influence the effectiveness of sectoral policies; they also create channels for technological diffusion as supplier and user firms interact.

Reversal

Where industries can rapidly substitute inputs, source globally, or adjust product portfolios, the propagation via historical linkages weakens; conversely, vertically integrated or specialized industrial structures intensify transmission.

Boundary

Clearly within: a supplier–buyer input–output relationship between automotive and steel industries. Boundary case: industries that share labor markets or regulatory regimes but limited transactional flows. Clearly outside: two industries that move together solely due to a common financial shock without material trade in goods or services.

Semantic Tension

Specialization/Efficiency ↔ Resilience — strong interindustry linkages increase efficiency via specialization but can reduce resilience by amplifying shocks across sectors.

Synthesis

Interindustry linkages are the structural channels through which production, demand, and technology effects travel across an economy; understanding their composition and substitutability is essential to predict propagation and to design targeted interventions.