THROUGHOUT the start-and-stop growth that has characterized the American economy in the past year, all eyes have been on the American consumer. Accounting for about 70 percent of the U.S. economy, consumers have kept the American and, indeed, the world economies from slipping into a deep recession by splurging on all manner of goods and services.

So much for the buy-side of the market. Less noticed is the revolution in the sell-side, the sector of the economy that is supplying the needs and wants of consumers. Start with automobiles. What were once seasonal price cuts designed to clear the lots at the end of the model year have become year-’round price reductions of as much as $5,000 on some vehicles. Manufacturers’ efforts to end the price wars have failed: consumers merely postpone purchases for the month or two that it takes the truce to collapse. Which it does with the regularity of the phony truces promised to the Iraqi government by Moktada al Sadr.