Because the interest rate automatically clicks up if the auction is a dud, hospitals, museums, universities and ports have suddenly found their debt-service bills rising sharply.

The creditors--TIAA-CREF and Prudential among them--hit Allen up for a 9% interest rate, which meant $14 million in annual debt service.

The research discovers that:(1) Whether enjoy the tax preference has the obvious influence to main camp service profit margin, property net profit rate and property ratio of debt.