http://bactra.org/notebooks Cosma's Notebooks en http://bactra.org/notebooks/1994/10/03#input-output The basic idea is that the outputs of some industries are the inputs of others, and you can keep track of this with a matrix. This can then be used to study the structure of industry, do planning, etc. The Air Force used in in WWII to decide which German factories to bomb, by seeing which industries were most vital --- the answer seems to have been ball-bearings. (From an unpublished chapter in my father's PhD thesis.) <P>Non-linear variants; dynamics. <ul>To read: <li>Erik Dietzenbacher and Michael L. Lahr (eds.), <cite>Wassily Leontief and Input-Output Economics</cite> [<a href="http://cambridge.org/9780521049436">blurb</a>] <li>Dorfman, Samuelson and Solow, <cite>Linear Programming and Economic Analysis</cite> <li>Dantzig, <cite>Linear Programming and Extensions</cite> <li>Gale, <cite>Theory of Linear Economic Models</cite> <li>Tjalling Koopmans, <cite>Efficient Allocation of Resources</cite> <li>Wassily Leontief, <cite>Input-Output Economics</cite> [<a href="http://www.oup-usa.org/gcdocs/gc_0195035275.html">Blurb</a>] <li>Charles W. McArthur, <cite>Operations analysis in the U.S. Army Eighth Air Force in World War II</cite> <li>Piero Sraffa, <cite>Production of Commodities by Means of Commodities</cite> <li>Thijs ten Raa, <cite>The Economics of Input-Output Analysis</cite> [<a href="http://cambridge.org/052160267X">Blurb</a>] </ul>