It anticipates a number of developments in distribution and growth theory and remains a standard work in labour economics.
[1] Part I of the book takes as its starting point a reformulation of the marginal productivity theory of wages as determined by supply and demand in full competitive equilibrium of a free market economy.
The 2nd edition (1963) includes a harsh critical review and, from Hicks, two subsequent related articles and an extensive commentary.
The Text of the First Edition (248 pages) Part I — The Free Market Chapter Part II — The Regulation of Wages Appendix [with discussion and mathematical proofs on statements in Chapter IV about absolute and relative shares of income (the "Social Dividend") relative to its elasticity of derived demand, with or without increasing returns] Section II.
Commentary (80 pages) [on respective earlier chapters and Section II documents, concluding with mathematical "Notes" on the elasticity of substitution as to its definition, generalization to multiple factors and products, and application to Marshall rules of derived demand]