With an Introduction by J.M. Keynes M.A., C.B.
f this coöperation is obtained by dwelling on the numbers of people who participate in it, or the immense distances over which it extends. The deficiency can be partially supplied by referring to some of the more obvious of the many subtle interconnections which exist between different commodities and different trades.
There are innumerable groups of commodities (which it is customary to term "joint products") such that the production of one commodity belonging to the group necessarily implies or very greatly facilitates the production of the others. Wool and mutton; beef and hides; cotton and cotton-seed are a few familiar illustrations. The important feature of these "joint products" is the fairly precise relation which must exist between the quantities in which the different products are supplied. If you plant a certain crop of cotton, it will yield you so much cotton lint and so much cotton-seed. You can, of course, if you choose, throw away part of the seed, as indeed at one time planters used to do;