Working Smarter, Not Harder: The Productivity Trap — Das Kapital

Marx opens Part IV by asking a precise question: if the working day is fixed at twelve hours, with ten hours necessary and two hours surplus, how can surplus-value grow without lengthening the day? The answer is relative surplus-value. Shrink necessary labour by cheapening the goods workers need to live.

That means raising productivity in industries that set the value of labour-power. No capitalist sets out to lower wages in general. Each simply tries to cut unit costs and beat rivals.

Yet the aggregate effect of that competitive drive is exactly what Marx describes: cheaper subsistence, shorter necessary labour, and a larger unpaid share of the same working day. Marx contrasts absolute surplus-value, gained by extending hours, with relative surplus-value, gained by revolutionising production itself. The innovator who doubles output can sell below social value and pocket extra profit until competitors adopt the method. Then the gain becomes general. Relative surplus-value is why capital constantly pushes productivity even while workers may still clock twelve, fourteen, or more hours. Efficiency does not automatically shorten the day for labour. It often lengthens the unpaid portion inside it.