FOR THEIR money -- something upwards of $150 billion of it -- taxpayers are entitled to a better explanation of the S&L disaster than they are now getting. With the approach of the congressional elections, it's degenerating to the level of the schoolyard and yes-you-did versus no-I-didn't. Neil Bush's relationship to his famous father has brought a good deal of attention to the collapse of the Denver S&L of which he was a director. That's part of the story, but only a small part. The biggest mistakes were not in Denver, but here in Washington.

The question is how best to obtain an account of this whole melancholy affair that is complete, authoritative and, as far as possible, unbiased. A first-term Republican from Vermont, Rep. Peter Smith, has offered a resolution -- and something more than half of the House has now cosponsored it -- calling on the president to appoint an independent counsel to investigate the part that government officials played in the savings and loan scandal. That's not a bad thought.

But the trouble with an independent counsel's investigation is that it focuses on crimes and criminal prosecution. As the country saw in the Iran-contra case, the necessities of prosecution can interfere severely with a full and public account of what went wrong in the political process. In the S&L bankruptcies, as in most great scandals, it was the political errors that came first and invited the crimes. Pursuing the crooks is important, but it's essential not to neglect the mistakes in policy.

It's an assignment that in other circumstances a congressional committee might undertake. But partisan interests have now risen to a point that would make it difficult for any committee to produce an account that would be generally accepted as credible and dependable. One possibility is a presidential commission, appointed equally by the president and the speaker of the House. Alternatively, Congress might find one person with sufficient reputation for impartiality to accomplish the job. The authority to hold hearings and to subpoena testimony would probably be necessary.

A full and reliable account would serve two highly valuable purposes. It would tell voters what happened to the public trust and allow them to fix blame on the basis of good information rather than on rumors and accusations. It would also help the government itself to avoid similar mistakes in the future. The entire banking system is now under great strain, and there may be serious trouble ahead. A short historical inquiry into the causes of the S&L collapses would be insurance against more expensive errors in the 1990s.