A Note on Non‐Stationary Prices

The concepts of ‘real'’ and ‘nominal’ values or ‘real’ and ‘nominal’ rates of profit in the presence of non‐stationary prices are discussed. It is shown that the rate of profit depends on the choice of the numeraire if—and only if—relative prices change over time. In this case there are as many real rates as there are products, factors or bundles of products and factors. Although the rate of profit may vary with the choice of the numeraire, the ranking of processes according to profitability—and hence the choice of technique—is not affected.