In fact, it has become increasingly difficult to pin down the notion of what constitutes a stable general price level. When industrial product was the centerpiece of the economy during the first two-thirds of the twentieth century, our overall price indexes served us well. Pricing a pound of electrolytic copper presented few definitional problems.
The price of a ton of cold rolled steel sheet, or a linear yard of cotton broadwoven fabrics, could be reasonably compared over a period of years. But in our new century, the simple notion of price has turned decidedly ambiguous. What is the price of a unit of software or a legal opinion?