Based on unproven allegations, President Donald Trump moved to fire a governor of America's central bank Monday evening. The Fed Governor Lisa Cook says the president does not have the authority to fire her and plans to stay on. In social media posts last week, Trump had claimed, without evidence, that there was fraud on a mortgage once taken out by Cook.

One of the strengths of the U.S. financial system has been a central bank that is not beholden to the impulses of politicians. Karen Petrou watches the Fed closely as the co-founder and managing partner of Federal Financial Analytics in Washington. She joined “Marketplace Morning Report” host David Brancaccio to discuss the legality of such a firing and the implications of eroding Fed independence. The following is an edited transcript of their conversation.

David Brancaccio: I want to ask you, do Federal Reserve governors like Lisa Cook serve at the pleasure of the president the United States, like, for instance, the President's Chair of the Council of Economic Advisers? The president could certainly fire that position, but what about a Fed governor?

Karen Petrou: No. The president cannot fire any member of the Federal Reserve Board at will. The only way the law allows the president to fire members of the Federal Reserve Board, including the chair, is for cause. And that means there has to be malfeasance or gross negligence for that to happen. The allegation here is that Lisa Cook committed mortgage fraud, but that is completely unproven, and, therefore, the extent to which there is cause is, at best, dubious.

Brancaccio: And one would expect some sort of formal process to determine whether or not Lisa Cook is at fault in some way?

Petrou: I like to think the United States [is a place] where you're innocent until proven guilty, even for for-cause allegations. What happened last week was there was an unproven allegation posted on Twitter by a government official. He called for a Justice Department criminal investigation. The next day, another official announced that he had found Ms. Cook guilty. Clearly, the day between an assertion posted on Twitter and the next day when a Justice Department official says, “Fire her," there is no investigation. There's no due process.

Brancaccio: The overarching issue here, I think, is central bank independence. It sounds like an abstract topic for a high school debate competition. But why should my friend Jeff, a carpenter from Manchester, New Hampshire, or my Aunt Vicky, a nurse, why should they care?

Petrou: First of all, I think we should all care about the integrity of the process. Congress intended the Federal Reserve to be insulated from politics because of the danger of political decision-making on so important an economic force. More importantly, Congress set up the Federal Reserve Board to be insulated from presidential authority because its independence is critical to credibility.

Brancaccio: One can imagine — to pick up on your point there — that it would be of concern to market professionals if a standoff emerges at the Fed — the president saying, "You're fired." A Federal Reserve Governor saying, "I'm still here." Whatever the next move is by either side, this can start to look not like the United States, but what you sometimes see in other countries.

Petrou: It can, and that's going to cost us all a lot — not just those of us with funds in the stock market, not those of us looking to buy a house a little bit down the road. This is all really costly. But the dollar right now is the global reserve currency, and that floats the government's boat, because the world trusts us; they give us their money and invest it in Treasury securities for a lot less than is demanded of higher-risk countries. The president has just made us a higher-risk country.