Of the group of three articles which follow the first two are reprinted from the Economic Joitrnal of December 1933 and December 1939, and are contributions to a discussion which occupied a good deal of attention among English economists in the 1930 s. Since the Second World War the debate among academic economists about the so-called pricing-problem under socialism has largely become, on this side of the Atlantic at any rate, a discussion about the price-policy for nationalised industries and the mechanism of economic planning. The most familiar element of discontinuity, widely discussed in recent economic literature, is the so-called indivisibility of capital equipment: a characteristic of much capital equipment is that it can only be supplied in units of a certain minimum size. As a rule, it has been assumed that in a socialist society the main propositions of economic theory would apply with undiminished force.