Progress and Poverty begins from a disturbing observation. The nineteenth century multiplied the power of labor through steam, machinery, and exchange, and reformers expected this to abolish poverty. Instead George finds that where progress is most advanced, in the densest and wealthiest communities, poverty is deepest and the struggle for existence sharpest. The persistence of want amid plenty is, he says, the great enigma of the times.
To explain it George re-examines the standard economics of his day. He disputes the doctrine that wages are drawn from capital and the Malthusian claim that poverty springs from population pressing on subsistence. In his account, labor produces wealth before capital exists, and the misery of crowded countries is not nature's stinginess but a problem of distribution. He clears these explanations away to make room for his own.
The book's analytical core is the law of distribution. George accepts the Ricardian law of rent, which fixes rent by the margin of cultivation, the least productive land in use. Production is shared among three parties: the laborer who receives wages, the capitalist who receives interest, and the landowner who receives rent. From the law of rent he derives that wages and interest depend on what is left after rent has been taken.
This yields his central thesis. As material progress increases population and refines production, it raises the value of land, and rising rent claims the gain. If, as production grows, neither wages nor interest rise, the landowner must reap the whole increase. In George's compressed phrase, rent swallows the gain and pauperism accompanies progress. The wedge of progress is driven through society rather than under it, lifting those above the line and crushing those below.
George's remedy follows from his diagnosis. Since the cause is private property in land, the cure is to make land common property, which he argues can be done without confiscating titles by abolishing all taxation save that upon land values and taking rent for public revenue. He defends this as justice, holding that the equal right of all to the use of land is as clear as the right to breathe, and closes by arguing that association in equality is the law of human progress.