Dodd-Frank not final chapter on reform: Dodd

Dodd-Frank: Four years later

Four years after the Dodd-Frank Wall Street Reform and Consumer Protection Act was signed into law, its co-authors told CNBC the law was doing its job, but said it certainly isn't the last chapter in regulating Wall Street and private equity firms.

"We didn't pass the Ten Commandments. We talked about a bill here, giving regulators the ability to modernize the architecture of our financial services industry," said former Sen. Christopher Dodd, who authored the law with former Rep. Barney Frank.

"Barney and I never envisioned we'd written the last and final chapter here of financial reform."

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The law was intended to provide stronger regulation of Wall Street the wake of the 2008 financial crisis. Republicans marked the anniversary Monday by releasing a report outlining the bill's failures. Four years later, not all of the required rules have been proposed.

Barney Frank, left, and Christopher Dodd in 2008
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However, Frank defended the law, pointing out many of the bill's accomplishments.

"The abusive mortgage loans that hurt consumers, that hurt financial institutions, that hurt the economy, we outlawed them and they haven't been made since then," he said.

"The consumer bureau has recovered a large amount of money for people. Derivatives are much more now market oriented. What some people claim were intrusive regulation, we're simply insisting that this be done in the market."

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Critics have said that too-big-to-fail financial institutions are still a hindrance to the economic recovery, and that too-big-to-fail should be eliminated.

However, Frank pointed out that they repealed the section of the Federal Reserve law under which allows the chair to advance money to an institution that is insolvent, like Ben Bernanke did with AIG.

"There's still big banks, and we have to pay attention, but they would not be propped up indefinitely with federal funds," Frank said.

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That said, it doesn't mean there won't be another financial crisis in the future, Dodd said.

"There will be another crisis, I promise you that. The question is will we be able to minimize it at the time and not become as large as the one we went through," he said.

—By CNBC's Michelle Fox.