Wassily Leontif:

Key contribution: Input-Output Model (IO)

1. Shows the critical interconnected structures links between sectors and industries.
2. Interconnections between consumption, investment, government expenditures and trade balance with includes exports, imports.
3. Captures inter-industry demand with necessary supply thus provides a necessary equilibrium of goods and services at particular intervals of time.
4. Direct forward linkages - the quantity by which an industry's product is demanded by other industries as inputs in their production process.
5. Direct Backward linkages - the quantity by which an industry demands other industry products for inputs in its own production process.

Provide examples of each contribution listed above