Airliners.net

I always thought that "yield" as used in the financial reporting of airlines was equivalent to revenue per passenger seat-mile . Note that I said per passenger seat-mile, not per available seat-mile. Or is it passenger revenue per available seat-mile? I'm confused because of the following excerpt from the US Airways financial highlights:

The yield of 13.36 cents for the first half of 2002 was down 12.9 percent from the same period in 2001, while passenger revenue per available seat mile of 9.60 cents was down 10.7 percent.

According to what I thought was the definition, yield(13.36) and prasm(9.60) should be equal. Can somebody explain and give me the correct definition of yield? Thanks.

Yield is computed based on per passenger-mile in the US, or per passenger-km outside of the US. Cost is computed based on per available seat-mile, or km.

Since load factor times total available seat-miles should equal to total passenger-miles, US Airways must have a load factor of 9.60/13.36*100 =71.9% in 2002.