The most familiar of his many contributions in the field of economics were his statement of consumer demand theory in microeconomics, and the IS–LM model (1937), which summarised a Keynesian view of macroeconomics.

[6] He started as a labour economist and did descriptive work on industrial relations but gradually, he moved over to the analytical side, where his mathematics background returned to the fore.

He donated the Nobel Prize to the London School of Economics and Political Science's Library Appeal in 1973.

[7] Heterodox Hicks's early work as a labour economist culminated in The Theory of Wages (1932, 2nd ed.

In the same year, he also developed the famous "compensation" criterion called Kaldor–Hicks efficiency for welfare comparisons of alternative public policies or economic states.

This model formalised an interpretation of the theory of John Maynard Keynes (see Keynesian economics), and describes the economy as a balance between three commodities: money, consumption and investment.

[9] Hicks's influential discourse on income sets the basis for its subjectivity but relevancy for accounting purposes.

“The purpose of income calculations in practical affairs is to give people an indication of the amount they can consume without impoverishing themselves”.

[11] Hicks's number 3 measure of income (takes into account market prices): “the maximum amount of money which an individual can spend this week, and still expect to be able to spend the same amount in real terms in each ensuing week” (Hicks, 1946, p. 174)[11]