Debate over whether to subject the Federal Reserve to a policy audit has occasionally focused on the size and composition of the Fed’s balance sheet. While I don’t see this issue as central to the merits of an audit, it has given rise to a considerable amount of smug posturing. Let’s step beyond the posturing and give these questions some of the attention they deserve.

First the facts. The Fed’s balance sheet has ballooned over the last few years to about $4.5 trillion. And yes, the Fed discloses such. No argument there. The Fed, like most central banks, has traditionally conducted its open-market operations in the “short end” of the market. The various rounds of quantitative easing have changed that. For instance the vast majority of its holdings of Fannie & Freddie mortgage-backed securities ($1.7 trillion) have an average maturity of well over 10 years. Similarly the Fed’s stock of treasuries have long maturities, about a fourth of those holdings in excess of 10 years.

Now the leverage question. We all get that the Fed cannot go “bankrupt” like Lehman. But that’s because “bankrupt” is a legal condition and one from which the Fed has been exempted. Just like Fannie and Freddie cannot go “bankrupt” (they are considered legally outside the bankruptcy code). The eminent economist historian Barry Eichengreen tells us the Fed’s leverage doesn’t matter as “the central bank can simply ask the government to replenish its capital, much like when a government covers the losses of its national post office.” Some of us would say that’s a problem not a solution, just like it is with the Post Office.

Others would suggest the Fed’s leverage doesn’t matter because “the Fed creates money”. Again that misses the point. Any losses could be covered by printing money, but isn’t that inflationary? And that, of course, is just another form of taxation. So it seems Senator Paul’s primary point, that the Fed’s balance sheet exposes the taxpayer to some risk has actually been supported, not discredited, by these supposed rebuttals.

Let’s get to another issue, the maturity of the Fed’s assets. There’s a good reason central banks generally stay in the short end of the market. It avoids taking on any interest rate risk. When rates go up, bond values fall. Yes the Fed can avoid recognizing those losses by simply not selling those assets. But that creates problems of its own. If we do see inflation, normally the Fed would sell assets to drain liquidity from the market. But would the Fed be willing to sell assets at a loss? At the very least there would be some reluctance. And yes they could cover those losses by printing money, but that’s hardly helpful if the Fed finds itself in a situation of rising prices.

The point here is that the Fed’s balance sheet does raise tough questions about its exit strategy. Perhaps the economy will remain soft for years and the Fed can exit gracefully. Perhaps not. I raised this possibility before Congress a year ago. I don’t know anyone with a crystal ball on these issues. But one thing is certain, this is a debate we should be having. Its the “nothing to see here, move along” crowd that poses the true risk to our economy.