Excess reserves and inflation risk

Dave Wheelock, my colleague at the St. Louis Fed, points me to this nice article: Repeat After Me: Banks Cannot and Do Not "Lend Out" Reserves (by Paul Sheard). I have noticed a few papers lately making the same general point. I thought I'd throw my own two cents worth in.

To begin, you have probably seen (or heard about) this scary picture (thank you, "Helicopter" Ben):


That's a picture of the U.S. monetary base--the liabilities of the Federal Reserve Bank consisting of either currency or currency-on-demand (held by private, not government agencies). The monetary base can be divided into two broad categories: [1] currency in circulation (currency held by the non-bank private sector); and [2] reserves (bank sector vault cash and credits in reserve accounts held at the Fed).

In light of the "explosion" of Fed money since 2008, it may seem surprising that inflation has averaged considerably less than the Fed's official 2% target:


A common explanation for this is that most of the new money created by the Fed is being held by banks as reserves. Banks would rather earn 25 basis points (IOER) than lend out their excess reserves.

The following diagram depicts the liability side of the Fed's balance sheet:


We see that currency in circulation has increased, but at a modest and steady pace. Most of the increase in base money (remember, green part not included in money base) consists of reserves. The inflation fear expressed by some rests on the question of what is likely to happen once the economy returns to "normal." Sooner or later, things are going to turn around and banks will want to lend out their excess reserves to earn a higher rate of return. What is going to happen when this tidal wave of money begins to circulate?

According to Paul Sheard, this line of thinking is all wrong. That is, while monetary policy may ultimately result in higher inflation (or not), if it does, it won't be through the "banks lending out their excess reserves" channel, as many seem to suggest.

To understand his point, let's begin with how the Fed actually creates money. The Fed is a bank. And like all banks, it buys (or lends against) high-interest assets, which it finances by issuing low-interest liabilities (profits are returned to the Treasury). When the Fed buys a security on the open market, it credits the seller's bank account with newly-issued electronic digits (reserves). Banks then have the option of redeeming their reserves for currency, an option they may exercise depending on their customers' demand for currency.

Now, individuals regularly make deposits and withdrawals of cash into and out of their bank accounts. The net flow of withdrawals minus deposits determines by how currency in circulation grows over time. Banks do not lend out their cash. When a bank makes a loan, it issues a deposit liability that is redeemable for cash on demand. The demand deposit liabilities can be used as a payment instrument (they constitute money, and are counted as part of a broader measure of money supply, e.g., M1). The key observation here is that the way currency enters the economy is through the net withdrawal activity of bank customers--it has nothing to dow with banks lending out their reserves.

Alright, so why is understanding all this important? Well, for one thing, it is an accurate description of the way money and banking actually works (as opposed to the traditional "money multiplier" story that is commonly told in undergraduate textbooks). It is the right place to start when thinking of policy questions.

In terms of thinking about the inflation risk associated with the size of the Fed's balance sheet, it guides us away from examining how bank lending (the money multiplier) may react to various shocks. Banks can try to lend out their reserves all they want (create new loans). But if the public is satisfied with their currency holdings, any money injected into the system in this manner would have no effect on bank sector reserves. Since it is bank customers that determine how much cash is withdrawn from reserves, we should instead think about the type of shocks that may potentially alter this redemption decision.

To begin, we have to think about a world in which the asset side of the Fed's balance sheet matters. In many macroeconomic models, it is implicitly assumed that the Fed has full support of the Treasury (e.g., lump-sum taxes can be used to drain the economy of excess money), so that the Fed balance sheet does not matter. We want to do away with that assumption. In this case, the only "money draining" tools available to the Fed are asset sales. That is, think about the asset side of the Fed's balance as a giant vacuum cleaner. The amount of power this vacuum has is related to the market value of the Fed's asset portfolio. Any shock that would significantly reduce the market value of the Fed's asset portfolio would be like having your vacuum cleaner malfunction (just when you needed it the most).  


So, what type of shock can we think about here that might lend credence to the idea that excess reserves pose an inflation threat? I'm not really sure, but maybe the story goes something like this. Suppose that inflation expectations suddenly become "unanchored." (for whatever reason, people expect higher inflation). Through the Fisher equation, we might expect a large increase in nominal interest rates. The spike in interest rates would imply a capital loss for the Fed. By how much? Consider this formula (an approximation):

1 ppt increase in interest rate = (average duration)% decline in asset price. 

The average duration of the Fed's asset portfolio is roughly 10 years. So a five percentage point increase in interest rates would induce a 50% decline in the value of the Fed's assets (actually, somewhat less than this, but you get the point).

Now, higher inflation expectations on the part of the public may induce people to want to hold more currency (in nominal terms--the demand for real money balances may decline). This may be what could trigger a mass wave of redemptions. As people start withdrawing cash from their bank accounts, the banks start redeeming their reserves for cash to meet their customers' demands. The spike in interest rates unplugs the Fed's vacuum cleaner -- people know that the Fed does not have the tools to buy back all of its reserve liabilities. The wave of redemptions proceeds unchecked, with the flood of currency generating an inflation that becomes a self-fulfilling prophesy.

Well, that's just a story. I'm not sure if it hangs together logically (I've never seen it modeled formally, though perhaps it has been?) And even if it has a logical foundation, I'm not sure how persuasive it is. I am curious to know what other story one might tell. However the story unfolds, it cannot be one of bank lending out their reserves. 

0 nhận xét:

Đăng nhận xét