5 ideas
Money can be held as a form of wealth, so demand for it cannot be pinned to transaction needs. Money's value relative to commodities therefore cannot be fixed by supply-demand equilibrium in the money market. Something outside the market must anchor money's value, or the price level has no determinate center of gravity.
The value of money is fixed by the money wage rate, which is set exogenously through social and institutional processes rather than by market clearing. Commodity prices are marked up over money wages. Money keeps its value only as long as money wages stay relatively stable, so wage-setting institutions are the real monetary anchor.
Unemployment and underemployment discipline workers' wage demands and keep money wages from spiraling upward. This makes the reserve army of labour a structural precondition for a stable-valued money, not just a by-product of accumulation. If the reserve army shrinks through sustained full employment, wage-price spirals threaten money's value and push the system toward crisis or policy-induced unemployment.
Metropolitan capitalism keeps money stable partly by relying on a colonial or peripheral hinterland. That hinterland supplies primary commodities at compressed prices and absorbs demand shortfalls. Squeezing primary-producer incomes through income deflation lets core economies keep near-full employment without inflation, pushing the adjustment burden onto the periphery. Money's stability in the core is therefore an imperial arrangement rather than a purely domestic one.
This lens treats a stable currency as evidence of underlying power relations rather than sound technical management. When money holds its value, you ask whose incomes are being suppressed to hold wages and input prices in place: domestic unemployed workers or peripheral commodity producers.