THERE ARE bureaucratic errors, there is congressional negligence -- and then there are bureaucratic errors and congressional negligence on a scale so vast that it is hard to believe they can be accidental. The hundreds of millions of dollars in unnecessary government payments to the student loan industry in the past 18 months amount to such a scandal. The loans in question, established in 1980, are guaranteed by the government at 9.5 percent. Yet most students are paying interest rates of 3.5 percent or less. The difference -- all taxpayers' money -- is pure profit for the companies that have taken advantage of a loophole in the law.

According to a recent report by the Institute for College Access and Success, a nonprofit education think tank, Congress had actually intended to end in 1993 the 9.5 percent loan guarantee, one of many programs that provide incentives for institutions to lend to students. In May 2003, one company, Nelnet Inc., wrote to the Education Department to confirm its intention to expand its holdings of old loans with the 9.5 percent interest rate. Nelnet received no answer from the department for a year, during which time the department continued paying the company. In June of this year, the department replied inconclusively -- at which point the company's stock price climbed 20 percent. Although Nelnet is the largest holder of loans guaranteed at 9.5 percent -- and its holdings of such loans have increased by 818 percent since January 2003 -- it is only one of many such lenders. According to a preliminary Government Accountability Office report, commissioned by Reps. Chris Van Hollen (D-Md.) and Dale E. Kildee (D-Mich.), 37 lenders receive payments for loans with guaranteed interest rates of 9.5 percent, at a government cost of $1 billion annually, and the volume of such loans is rising.

Why wasn't the loophole shut long ago? Education Department officials argue strenuously that only a two-year regulatory process could have done so, and they didn't initiate one, they say, because they thought Congress would deal with it. Congressional Republicans say they expected to deal with the problem in a comprehensive higher education bill, but that has failed to pass (and in any case the proposed language would not have ended all the payments). Yet, other solutions could have been found: In the wake of revelations about the scale of the payments, the House yesterday passed an amendment to an appropriations bill, offered by Mr. Van Hollen and Mr. Kildee, that would close the loophole completely, albeit temporarily. (Of course, there is no guarantee it will become law.) And one former Education Department general counsel has written to the secretary of education, Roderick R. Paige, arguing that the loophole could have been closed immediately if officials had wished to do so.

There could be other explanations for their reluctance. One is that the president of Nelnet, Don R. Bouc -- who has called for the loophole to be shut and the money to be better used -- is well-connected enough to have been appointed to Mr. Paige's advisory committee on student financial assistance. Here is another: According to a report in the Chronicle of Higher Education, Nelnet is the second-largest contributor to congressional campaigns in the student loan industry, beaten only by industry giant Sallie Mae. Over the past 18 months, the student loan industry has contributed about $750,000 to the 49 members of the House Committee on Education and the Workforce, of which $136,000 has gone to the committee chairman, Rep. John A. Boehner (R-Ohio), and $175,000 to Rep. Howard P. "Buck" McKeon (R-Calif.), chairman of the subcommittee on higher education. Mr. Boehner's spokesman vehemently denies any connection between the contributions and the issue and maintains that the committee's bill would have fixed the problem, which was mentioned in the president's latest budget. Still, it is difficult to understand, given the sums involved, why neither Mr. Paige nor Congress made this a higher priority.

For nearly a decade we have argued that Congress should reduce subsidies for banks that lend to students, and instead expand the direct-loan program, which provides about a quarter of student aid -- or else reform the system to make it harder to manipulate. This scandal provides an excellent reason to look again at these questions.