But when I moved to implement regulation prohibiting accounting firms from doing auditing and consulting work for the same companies, the Big Five firms threatened litigation, saying we had to do a cost-benefit analysis. Problem was, the big audit firms alone held the cost data. We asked them for those data, which they declined to provide.

Meanwhile, the benefits of the proposed rules were clear to me — they would have raised investor confidence in the quality of audits — but were difficult to quantify with precision. We were stuck, and the rule proposal died.

The fact that the S.E.C. was vindicated later, when these audit conflicts were identified as one of the accelerants of the dot-com bubble and our proposed independence rules were incorporated into the 2002 Sarbanes-Oxley securities law, is of little solace to me.

I would much rather have Congress recognize that cost-benefit work requires that the commission have significantly more power and resources to gather and analyze data. What we need is not a requirement to do more cost-benefit analysis, but better tools to do the work well and with more precision. Otherwise, cost-benefit analysis will become a permanent and immovable wall to future efforts to improve the stability, safety and transparency of financial markets.

Ultimately, the reason to oppose Congressional defunding of the S.E.C. and the Bachus legislation is even more straightforward. The S.E.C. is an independent agency that is designed to operate with minimal political interference. If it and other independent agencies — like the Federal Reserve, the National Labor Relations Board or the Federal Election Commission, to name just a few — did not have, through law and precedent, significant independence and necessary support, the work of these agencies would be more politicized, and as we know from past experience, less effective.

If Congress has decided that it no longer wants these agencies to operate independently, so be it. But they should follow through by deauthorizing the agencies outright — not by defunding them or passing laws that emasculate them under the false guise of modernization.