1 - D. Dillard The Economics of John Maynard Keynes London 1956

I think this is the relevant book but cannot get hold of it.

2 - J. Robinson Essay in the Theory of Economic Growth London 1962
I think this is the relevant book but can't get hold of a copy

4 - J.M. Keynes The General Theory of Employment Interest and Money London 1949

5 - The General Theory of Employment Interest and Money J.M. Keynes London 1949

page 307-8

During the nineteenth century, the growth of population and of invention, the opening up of new lands, the state of confidence and the frequency of war over the average of (say) each decade seem to have been sufficient, taken in conjunction with the propensity to consume, to establish a schedule of the marginal efficiency of capital which allowed a reasonably average level of employment to be compatible with a rate of interest high enough to be psychologically acceptable to the wealth owners''' This was not accidental. It is rightly described as due to a balance of forces in an age when individual groups of employers were strong enough to prevent wage-unit from rising much faster than the efficiency of production, and when the monetary systems were at the same time sufficiently fluid and sufficiently conservative to provide an average supply of money in terms of wage-units which allowed to prevailthe lowest average rate of interest readily acceptable by wealth owners under the influence of their liquidity preference. The vaerage level of employment was, of course, substantially below full employment, but not intolerably below it as to provoke revolutionary changes. Today and presumably in the future, the schedule of the marginal efficiency of capital is, for a variety of reasons, much lower than it was in the nineteenThe State will have to exercise a guiding influence on the propensity to consume partly through its scheme of taxation, partly by fixing the rate of interest, and partly, perhaps, in other ways. Furthermore, it seems unlikely that the influence of banking policy on the rate of interest will be sufficient by itself to determine an optimum rate of investment. I conceive therefore that a somewhat comprehensive socialisation of investment will prove the only means of securing an approximation to full employment; though this need not exclude all manner of compromises and all devices by which public authority will cooperate with private initiative.
J.M. Keynes op. cit. p. 378

- th century.

20 - I expect to see the State, which is in a position to calculate the marginal efficiency of capital goods on long view and on the basis of general social advantage, taking an even greater responsibility for directly organising investment; since it seems likely that fluctuations in the market estimation of the marginal efficiency of different types of capital, calculate on the principles I have described above, will be too great to be offset by any practicable changes in the rate of interest.

J.M. Keynes op. cit. page 164