Business airfares in the U.S. jumped 12 percent in 2000, according to the American Express Business Travel Monitor, released at the end of January. This was double the rate of increase in both 1999 and 1998.

To buffer the sticker shock at airports, companies took advantage of corporate discount fares and nonrefundable leisure fares, according to the study (which defines a business fare as the lowest-priced, fully refundable economy-class ticket with no more than three days advance purchase). Nevertheless, even when factoring in these savings to arrive at another business travel category, the “average price paid,” American Express found a fare increase of 6 percent, versus 2 percent in 1999 and 1998.

American Express tracks five airfare indicators — first class, full coach, typical business, lowest discount, and average fare paid — across 215 domestic city pairs each month.