Friday, October 20, 2017

The Other Side of the Fed's Balance Sheet

Who controls the Fed's balance sheet? The answer may seem obvious. The Fed, after all, determines the size of its balance sheet. It also controls what happens to the asset side of its balance sheet. Its power over the liability side, however, is limited.

This diminished control arises because the public's demand for currency, bank regulations, and U.S. Treasury cash balances all influence the composition of the Fed's liabilities.1 These are exogenous forces that have the potential to create some economic bumps on the road ahead as the Fed normalizes the size of its balance sheet. 

So far, though, little attention has been paid to these liability-side issues. Most focus has been given to the asset side of the Fed's balance sheet. This focus, in my view, is misguided. I see the real dangers lurking on the liability side of the Fed's balance sheet--the very side where the Fed has less control. 

This post, then, is attempt to direct some attention to the liability side of the Fed's balance sheet. In it, I first explain how the public's demand for currency, bank regulations, and the U.S. Treasury cash balances are beyond the Fed's control but affect its balance sheet. I then explain how these forces and current Fed policy could interact in a disruptive manner.  

The Public's Demand for Currency
Consider first the public's demand for currency. It grows as the dollar size of economy grows. This growing demand for currency is met by banks turning reserves into currency. Some of this growing demand for currency comes from foreigners and some from domestic residents. As seen in the figure below, both have grown over the past decade. In total, currency grew from around $800 billion in 2007 to $1.58 trillion today. The almost $800 billion increase in currency means a similar-sized decline in reserves over the same period.

This development matters because the nearly $800 billion loss of reserves and gain in currency was largely beyond the Fed's control. Put differently, the Fed controls the initial level and form of bank reserves, but it loses control over time. If the Fed were trying to stabilize a certain level of reserves--say to keep its floor system working--this steady growth of currency demand makes it harder. This is a powerful force with which the Fed has to contend. 

Now the currency demand growth may be seen as plus since it reduces the amount of balance sheet reduction required going forward. But it also poses some challenges that I will discuss later. For now, note that the growth in currency demand is an exogenous force that steadily tugs at the composition of the liability side of the Fed's balance sheet. 

New Bank Regulations
There have been a lot of new bank regulations since the crisis, but here I want to focus specifically on the liquidity coverage ratio (LCR). It requires banks to hold enough "high-quality liquid assets" (HQLA) to withstand 30 days of cash outflow. Unsurprisingly, the LCR has increased demand for HQLA assets. In particular, it has increased demand for bank reserves and treasury securities which can be held at full value (other assets, like GSEs can be held but at a discount). The LCR was implemented in January 2015.

Per the LCR, bank reserves and treasuries are equally safe and banks should be indifferent between holding them for regulatory reasons. Per the banks, however, they are not the same. The IOER paid on excess reserves has been consistently higher than the yield on short-term treasury bills as seen below. This raises the demand for bank reserves relative to treasury securities.  

So the IOER being greater than other short-term market rates raises the relative demand for bank reserves and the LCR, which is beyond the Fed's control, intensifies this demand. 

U.S. Treasury Cash Balance
The U.S. Treasury Department is also an exogenous force affecting the Fed balance sheet. There are several channels of influence, but here I want to focus on Treasury's cash balances that are deposited at various places. These deposits can broadly grouped into two categories: (1) interest-earning deposits held at private financial firms and (2) non-interest earning deposits held at the Fed in the Treasury General Account (TGA).

Prior to 2008, Treasury kept most of its cash balances outside the Fed. This earned interest for the taxpayers and also made life easier for the Fed since the TGA was small. After 2008, this pattern reversed: Treasury parked most of its cash balances at the Fed and vastly expanded their size. This can be seen in the figure below:

The main reason for this big shift in 2008 was that the IOER rate has been higher than short-term market interest rates. Here is why this matters. Treasury funds deposited at private banks become reserves that get redeposited at the Fed so that banks can earn IOER. The IOER payments going from the Fed to the banks are payments not going to Treasury. Moreover, the IOER payments exceed what Treasury can earn on their deposits at private banks because IOER exceeds short-term deposit rates.2 

Treasury, consequently, was losing income after IOER. Treasury officials quickly realized they could minimize this loss by pulling their funds out of private financial firms and instead park them at the Fed in the TGA.By doing so, however, Treasury officials were pulling out reserves from the banking system and therefore shrinking the aggregate level of bank reserves. This change in the composition of the liability side of the Fed's balance sheet was beyond the Fed's control. 

Putting it All Together
So we have we have currency demand growth, LCR, and the TGA all exogenously affecting reserves on the liability side of the Fed's balance sheet. In addition, the Fed is affecting the demand for reserves with IOER being greater than market interest rates. The Fed is also draining reserves via its balance sheet reduction program and its overnight reverse repo program (ON-RRP). The table below summarizes these developments.

The figure below shows how these forces have affected the growth of the liability side of the Fed's balance sheet so far:

Potential Disruptions Ahead
These developments matter because, as seen in the table, they are pushing the supply and demand for reserves in opposite directions. 

Bank reserves have been shrinking because of currency demand growth, the TGA, and ON-RRP. At the same time the demand for reserves has been elevated because IOER is greater than short-term market rates. Since 2015, this demand has been elevated because of the LCR. And now the Fed is about to further heighten this imbalance by draining reserves as it begins shrinking its balance sheet. 

The figure below shows this is more than just a theoretical concern. It shows the level of bank reserves since 2015 (when the LCR started) plotted against the spread between the overnight dollar libor rate and the 1-month treasury rate. There is a negative relationship which means as reserves fall the libor rises relative to the treasury bill rate. The increases are not terribly large and this only explain a third of the variation in the spread since 2015, but it does suggest further tightening will occur moving forward if nothing else changes as the Fed shrinks its balance sheet. 

So what should the Fed do? It could curtail the shrinking of its balance sheet, but that is not the path I would chose. The balance sheet reduction is already baked into market expectations and it should continue for other reasons outlined here

What it should do, in my view, is aim to bring the IOER closer to market interest rates. I am not sure how easy this task would be, but it would reduce the heightened demand for reserves, lower the TGA, and soften the bite of the LCR.  One way to help push the IOER closer to market rates would be for the Fed to announce a corridor system as the final destination for the Fed's balance sheet reduction. This has not happened yet, but it should be something the FOMC seriously considers.

1 There are some other exogenous forces on the liability side that I ignore here. The biggest one being foreign official accounts at the Fed. These, however, generally are not too large and therefore less consequential.
2 This was due both to IOER being greater than short-term market interest rates, but also because by law Treasury can only earn 25 basis points less than the federal funds rate at depository institutions. Treasury can also park funds in repos and in term deposits, but even these earn less than the IOER. See this NY Fed piece for more on Treasury cash balances.
3The IOER incentive to park funds in the TGA was reinforced by new Treasury policy in 2015 that raised the minimum size of the account to $150 billion. 

Sunday, October 8, 2017

From a Floor System to A Corridor System

So I was looking at the Fed's 2016 annual report and was able to construct the following chart:

Several observations from this figure. First, the sharp growth in the Fed's income is unsurprising as it is a natural consequence of the Fed's QE programs. These large scale asset purchase programs expanded the Fed's assets from around $900 billion in late 2008 to $4.5 trillion today. Moreover, the Fed's portfolio has changed from being mostly short-term treasury securities to one of long-term treasury and agency securities. In addition, the Fed also started paying interest on excess reserves (IOER) to banks during this time. Together, these two developments have effectively turned the Fed into the largest fixed-income hedge fund in the world. Hence, the surge in the Fed's income. 

Second, the Fed's net expenses have also grown rapidly since 2008. Fed officials will point to new financial regulations they have to enforce as the main culprit, but there is arguably a political economy story to the surge as well. Interestingly, this surge accelerated between 2015 and 2016 as seen in the figure. There is no mystery behind this uptick. It is almost entirely the result of the larger IOER payments going to banks as interest rates have gone up. This can be seen in the following numbers:

The IOER payments are expected to grow as the Fed continues to tighten policy. Assuming this tightening does not get ahead of the recovery and cause a recession, future IOER payments should grow as seen in this chart fromThe Economist:

The Fed estimates these payments could hit $50 billion by 2019. And, as a reminder, most of these payments will be going to large domestic banks and foreign banks as they hold most of the excess reserves. This can be seen in the figure below:

So expect the Fed's net expenses to keep growing at a healthy pace for the next few years as it pays out larger and larger IOER payments to large domestic and foreign banks. As I have argued before, this is bad optics and will make the Fed's large balance sheet an increasingly toxic issue for Fed officials. Something will have to give.

Here is my suggestion for the Fed: move to a corridor system. It would still give the 'interest rate control' feature the Fed desires but with a much smaller balance sheet. In a corridor system, the IOER would become the floor for the federal funds rate and the discount rate (or the TAF) would set the ceiling. The figure below shows the difference between a corridor system and floor system. As noted by Stephen Williamson and George Selgin, a corridor system has been working well in Canada with a relatively small balance sheet. 1

Not only is the Fed's large balance sheet bad optics, it really does not pack much punch in normal economic circumstances. So a corridor system makes a lot of sense: it maintains interest rate control, facilitates better politics, and creates a concrete end goal for the Fed's normalization plans that is not disruptive.  Moving to a corridor system should be one of the key objectives for the next Fed chair and the FOMC. 2

1Technically, the Fed has what Stephen Williamson calls a 'sub-floor' system or what George Selgin calls a 'leaky floor' system. Thus, there is a floor beneath the floor, the RRP rate which catches the  financial 'leaks' which make it through the IOER rate. Still, the IOER guides all the other rates and is the main instrument of policy.
2It goes without saying that another key objective for the next Fed chair and the FOMC should be a move towards a NGDPLT. Both this and the move to a corridor system would be complementary. 

Thursday, September 21, 2017

The Future Path of the Monetary Base and Why It Matters

Now that the shrinking of the Fed's balance sheet has been announced, I thought it worth nothing what it means for the future path of the monetary base. Drawing upon the Fed's median forecast of its assets through 2025 that comes from the 2016 SOMA Annual Report, I was able to create the figures below. 

The figures show the trend growth path of currency and a series I call the 'permanent monetary base' extrapolated to 2025. The latter series is the monetary base minus excess reserves. This measure has been used by Tatom (2014) and Belongia and Ireland (2017) as a more reliable indicator of the monetary base that actually matters for monetary conditions. These two measures, which reflect the liability side of the Fed's balance sheet, are plotted along side the projected path of the asset side of the Fed's balance sheet. The first figure below shows this exercise in terms of dollars and the latter one is in log-levels.

What is interesting is that the Fed's median forecast of its assets eventually converges with the trend growth of currency which historically has made up most of the monetary base. Unsurprisingly, the permanent measure of the monetary base also tracks currency's trend path. Jim Hamilton does something similar here.  

So what are the takeaways? First, the Fed is expecting to confirm the temporary nature of the monetary expansion  under the QE programs. That is, the only major growth in the monetary base the Fed expects to persist is that coming from the normal currency demand growth that follows the growth of the economy. This endogenous money growth would have happened in the absence of QE. 

Second, the temporary nature of the QE programs, implied by these figures, is a key reason why these programs did not spur a robust recovery. For reasons laid out in this blog post and in this forthcoming article, there needed to be some exogenous permanent increase in the monetary base to spur robust aggregate demand growth. It never happened and neither did the much-needed recovery.  Instead we got the monetary regime change we never asked for.

Update I: See George Selgin's take on why QE was not very effective.

Update II: Brian Bonis, Jane Ihrig, and Min Wei from the Board of Governors just posted a note with the latest forecast of the Fed's balance sheet. It is updated to include the latest information from the recent FOMC meetings. My figures come from an earlier forecast and are a bit dated relative to these numbers. Their forecasted end value for the SOMA holdings ranges from $2.6 to $3.2 trillion. The median forecast I used above ends up at $3.2 trillion. So my trends would fit their high end estimates. 

However, their note is more nuanced than my graphs above. While they recognize that currency demand growth will be a big determinant of the future size of the Fed's balance sheet, they also recognize that depending on what the Fed does and what happens to banking regulation there could be an additional buffer in the Fed's balance sheet from excess reserves. Here is an extract:
Normalization of the size of the balance sheet occurs when the securities portfolio reverts to the level consistent with its longer-run trend. This trend is determined largely by the level of currency in circulation and a projected longer-run level of reserve balances. There is a great deal of uncertainty about the longer-run level of reserves, which could be affected by factors such as structural changes in the banking system, the effects of regulation on banks' demand for reserves, and the Committee's ultimate choice of a long-run operating framework. We show two scenarios. We assume that the longer-run level of reserve balances is either $100 billion (as in our April 2017 projection) or $613 billion (the median response from the Federal Reserve Bank of New York's June 2017 Survey of Primary Dealers and Survey of Market Participants)
Here are the relevant charts from their note:

The Political Economy of Shrinking the Fed's Balance Sheet

Most folks know the arguments for and against shrinking the Fed's balance sheet on purely economic terms. For a good recap of these arguments see Cardiff Garcia, Henry Curr, and Nick Timiraos. There are however, other political economy forces at work that potentially play into the Fed's decision to shrink its balance sheet.

Most folks do not go there because it is a controversial approach. For it takes a more cynical view of government officials. It goes beyond the view of the Fed as a technocratic institution filled with saintly people doing their best to stabilize the business cycles. It recognizes that people are people no matter where they work and are responsive to political incentives. Now to be clear, many good people work at the Fed because they believe in the mission. But to say the mission is the only thing they consider would be naive. Fed officials, like most people, also care about their own well-being. On the margin, this influences their decision making at the Fed.

This political economy critique of the Fed is not a new one. Mark Toma has entire book on the topic. But most observers, including myself, rarely apply it to the Fed. This includes recent discussions about the Fed's decision to shrink its balance sheet.

I wrote an OpEd for The Hill that bucks this trend. It looks at two countervailing political economy forces weighing on the Fed's decision to shrink its balance sheet. The first force incentives the Fed to keep its balance sheet large:
The large-scale asset purchasing program, better known as quantitative easing, caused the Fed’s balance sheet to grow from roughly $900 billion in late 2008 to $4.5 trillion. 
This vast expansion, combined with the introduction of the Fed’s program to pay interest on excess reserves (IOER) to banks, effectively transformed the Fed from a standard central bank into one of the most profitable financial firms on the planet... 
Over the past few years, it has averaged near $100 billion in profits. Prior to the crisis, its profits averaged only $25 billion per year. The Fed’s profitability has allowed its budget to grow 4.1 percent per year between 2007 and 2017, compared to 2.4 percent for the federal government. 
Given the profitability, prestige and jobs created by maintaining the Fed’s large balance sheet, it will not be painless for the Fed to shrink it.
Yes, the Fed remits most of its profits to the Treasury, but its own budget has grown relatively fast under its large balance sheet as noted above. Here is a chart from the Fed's 2016 annual report that illustrates this development:

Now some may say this increased spending is due, in part, to the new regulatory responsibilities the Fed has taken on since the crisis. Maybe so, but the Fed has been one of the biggest champions of its new regulatory role. Whether you believe the Fed is a good regulator or not, it has an incentive to expand its budget, prestige, and influence over finance via its regulatory role. Keeping its balance sheet large helps facilitate this expansion. So this is a political economy force for keeping its balance sheet large.

The second force I note in my OpEd incentives the Fed to shrink its balance sheet:
[T]he Fed may be eager to unwind its balance sheet [because] it is bad optics politically. The large expansion of the Fed’s asset holding accompanies a similar-sized expansion of its liabilities. 
Most of the increased liabilities have been in the form of banks’ excess reserves. Banks deposit these at the Fed and earn the IOER payment. As seen in the figure below, almost all of the excess reserves parked at the Fed are cash holdings of foreign and large domestic banks. 

That means foreigners and the U.S. banks bailed out during the crisis are getting most of the interest payments from the Fed. If the Fed’s balance sheet was maintained and short-term interest rates eventually rose to 3 percent (as expected), these banks would get approximately $66 billion a year from the Fed. 
To illustrate this point, we again go back to the Fed's 2016 annual report. It shows the Fed's net expenses jumped from roughly $11 billion in 2015 to $17 billion in 2016. That is a huge percentage increase. Almost of all it came from the large IOER payments the Fed had to pay in 2016 because of higher interest rates. Specifically, the IOER payment went from $6.8 billion in 2015 to $12.1 billion in 2016. This is horrible optics: the Fed's expenses are ballooning because it is paying more to foreign banks and the large U.S. banks we bailed out. The Fed can avoid this controversy by shrinking its balance sheet.

As I note in the piece, it is not often that an important government agency voluntarily agrees to actions that will reduce its budget and reach. Yet, the Fed is doing just that by shrinking its balance sheet. It suggests to me that the IOER issue, in conjunction with the other reasons stated by the Fed for shrinking its balance sheet, may be more important than many observers now realize. 

P.S. The above assumes the Fed actually goes through with shrinking its balance sheet. I mention in a previous post that the IOER-treasury bill spread if left uncheck may prevent that from happening.

Monday, September 18, 2017

Is Larry Summers a Fan of Nominal GDP Level Targeting?

You are going to have listen to my podcast with him to find out the answer. Here is a hint: we spent a portion of the show talking about NGDP level targeting (NGDPLT) and what it would take to actually get it implemented it at the Federal Reserve. So listen to the show to find out Larry's thoughts on NGDPLT as well as his views on secular stagnation, Fed policy since the crisis, and macroeconomic policymaking in real time. It was a fun interview. 

P.S. You can also read the transcript of our interview.
P.P.S. For those interested in NGDPLT here is my latest policy brief on it and here is a longer research paper on it.

Will Shrinking the Fed's Balance Sheet Matter?

This week the Fed is expected to announce it will begin shrinking its balance sheet. Will it matter? 

To answer that question it is useful to first recall how and why the Fed's balance sheet was expanded. Between December 2008 and October 2014 the Fed conducted a series of large scale asset purchases (LSAPs) that expanded its balance sheet from about $900 billion to $4.5 trillion. That is an expansion of about 500 percent. 

The Fed turned to LSAPs for additional stimulus when its target for the federal funds rate—the traditional tool of U.S. monetary policy—hit the zero lower bound in late 2008. The main theory the Fed used to justify the LSAPs was the portfolio balance channel. It says that because of market segmentation the Fed's purchase of safe assets would force investors to rebalance their portfolios toward riskier assets. This rebalancing, in turn, would reduce risk premiums, lower long-term interest rates, and push up asset prices. This would help the recovery. 

LSAPs were supposed to trigger the portfolio balance channel by reducing the relative supply of safe assets to the public. This reduction in safe asset supply to the public can be seen by looking at the growing share of safe assets held by the Fed under the various QE programs. The Figure below shows this development for marketable U.S. treasury securities:

This figure also shows another development that has taken place since late 2014: the Fed's share of treasuries has been shrinking. I call this the Fed's "reverse QE" program. Per the portfolio channel, this should be a passive tightening of monetary policy as the Fed's share of safe assets has fallen. Put differently, this should be portfolio rebalancing in reverse that causes long-term treasury yields to rise. 

The figure below, however, shows the opposite has happened under "reverse QE". Other than the Trump bump, 10-year treasury yields have been heading down. Even if we focus just on the ZLB period of "reverse QE"--October 2014 through December 2015--we still see this pattern:

So what does this all mean? It suggests that outside of the 2008-2009 crisis period the portfolio balance channel never really mattered. There are good theoretical reasons for this conclusion as noted by Michael Woodford, John Cochrane, and Stephen Williamson.1 It is not clear, then, that QE2 and QE3 made much difference to the recovery. To be clear, there is some empirical evidence that shows some small-to-modest results for these programs. Even if these results are taken as given, however, most evidence points to this success coming from the signaling channel rather the portfolio balance channel.2

This implies the Fed's shrinking of its balance sheet should not be a big deal. The Fed has been signaling for some time it would start shrinking its balance sheet this year. It even released a detailed plan in June of how it will happen. So there should be no surprises--the Fed is carefully using the signaling channel to keep markets calm. Given this signaling and the lack of a binding portfolio balance channel,  the concerns about the shrinking of the Fed balance sheet causing monetary policy to tighten are mostly noise.

I say mostly noise because there is one potential concern. It is the financial pressure caused by the new regulatory demands of the liquidity coverage ratio running up against the spread between IOER and treasury bills. I wrote about this issue awhile back in an OpEd:
The second reason the scaling back of the Fed's balance sheet may be challenging is that post-2008 regulation now requires banks to hold more liquid assets. Specifically, banks now have to hold enough high-quality liquid assets to withstand 30 days of cash outflow. This liquidity coverage ratio has increased demand for such assets of which bank reserves and treasury securities are considered the safest. So, in theory, as the Fed shrank its balance sheet, the banks could simply swap their excess reserves (that the Fed was pulling out of circulation) for treasury bills (that the Fed was putting into circulation). The challenge, as observed by George Selgin, is that the Fed's interest on excess reserves has been higher than the interest rate on treasury bills. This creates relatively higher demand for bank reserves.  
Banks would not want to give up the higher-earning bank reserves at the very moment the Fed was trying to pull them out of circulation. This tension could create an effective shortage of bank reserves and be disruptive to financial markets. The solution here would be for the Fed to lower the interest on excess reserves to the level of treasury bill interest rates.
The figure below illustrates this potential problem. It shows the Fed's upper and lower bounds on the federal funds rate and the 1-month treasury bill interest rate. These upper bound is the IOER and the lower bound is the reverse repo rate. The reverse repo rate has (sort of) anchored the 1-month treasury bill yield, but the issue is the spread between it and the IOER. Why would  banks want to give up bank reserves for treasury bills when reserves earn at least 25 basis points more than treasury bills? The Fed will be pushing against this demand when it tries to pull the excess reserves out of the banking system. Good luck wth that. 

To summarize, we need not worry about the portfolio balance channel kicking into reverse as the Fed begins shrinking its balance sheet. We should, however, worry about the distortions created by the positive IOER-treasury bill yield spread as Fed unwinds its asset holdings. The Fed can fix this problem by equalizing IOER and short-term market interest rates.

Update: Cardiff Garcia reviews a research note by Nomura's Lew Alexander on shrinking the Fed's balance sheet. Also, Nick Timiraos has a nice long piece on the Fed's LSAPs in the WSJ.
1Theoretical Problems with the Portfolio Balance Channel. The portfolio balance channel as envisioned by the FOMC relied on controversial assumptions about segmented markets and the Fed being a more efficient financial intermediary than other financial firms. On the first assumption, if the Fed can truly affect long-term treasury interest rates because the long-term treasury market is segmented from other markets, then by definition actions in the treasury market should not spill over into other markets. Put differently, portfolio rebalancing cannot take place in truly segmented markets. On the second assumption, if the Fed takes duration risk off of private-sector balance sheets via LSAPs, the risk really has not gone away since those long-term assets are now on the Fed’s balance sheet which, in turn, is backed-up by the tax payer. The private sector is still bearing the risk. The Fed, in other words, is not some special financial intermediary that can transform and diversify away the riskiness of the assets it purchases. This is the Modigliani-Miller theorem critique applied to central bank asset purchases as shown by Wallace (1981). Ben Bernanke acknowledged this theoretical tension by famously quipping that the “problem with QE is it works in practice not in theory.”

During the financial crisis the above assumptions were probably reasonable when markets froze up and the Fed become the lender of last resort. So QE1 probably made a meaningful difference. But after the crisis it is hard to make a convincing case for the assumptions holding. That is why QE2 and QE3 probably did not pack much punch. See Stephen Williamson, John Cochrane, or Michael Woodford (p. 61-65) for more on the theoretical problems with the Fed's understanding of the portfolio balance channel.

2The signaling channel is based on the idea that the LSAPs indicate a firm commitment by the Fed to keep interest rates low for a long period that would not be evident in the absence of the LSAPs.

Friday, September 15, 2017

Monetary Regime Change: Mission Accomplished

Christina Romer, former CEA chair, called for a monetary regime change several times between 2011 and 2013. It is now several years later and it appears we did finally get a monetary regime change. Unfortunately, it is not the kind of regime change Christina advocated and actually goes in the opposite direction. 

Christina called for the Fed to adopt a nominal GDP level target that would restore aggregate demand to its pre-crisis growth path. Instead, we got a regime change that has effectively lowered the growth rate and the growth path of aggregate demand. This regime change, in my view, is behind the apparent drop in trend inflation that Greg Ip recently reported on in the Wall Street Journal. 

It is not easy to change trend inflation--just ask Paul Volker--but the Fed and other forces seemingly accomplished just that over the past decade. Since the end of the crisis, the average inflation rate on the Fed's preferred measure of inflation, the core PCE deflator, has fallen to 1.5 percent The headline PCE deflator average has fallen to 1.4 percent over the same period. Both are well below the Fed's target of 2 percent. 

This persistent shortfall of inflation has received a lot of attention from critics, including me. Lately, some Fed officials are also beginning to see the inflation shortfall as more than a series of one-off events. Governor Lael Brainard's recent speech is a good example of this change in thinking with her acknowledgement that trend inflation may be falling.

Still, there is something bigger going on here that is being missed in these conversations about the inflation rate. A monetary regime change has occurred that has lowered the growth rate and growth path of nominal demand. Since the recovery started in 2009Q3, NGDP growth has averaged 3.4 percent. This is below the 5.4 percent of 1990-2007 period (blue line in the figure below) or a 5.7 percent for the entire Great Moderation period of 1985-2007. Macroeconomic policy has dialed back the trend growth of nominal spending by 2 percentage points. That is a relatively large decline. This first development can be seen in the figure below.

The figure above also speaks to the second part of this regime change: aggregate demand growth was not allowed to bounce back at a higher growth rate during the recovery like it has in past recessions. Historically, Fed policy allowed aggregate demand to run a bit hot after a recession before settling it back down to its trend growth rate.  This kept the growth path of NGDP stable. You can see this if the figure above by noting how the growth rate (black line) typically would temporarily go above the trend (red line) after a recession.  

Had macroeconomic policy allowed aggregate demand growth to follow its typical bounce-back pattern after a recession, we would have seen something like the blue line in the figure. This line is a dynamic forecast from a simple autoregressive model based on the Great Moderation period. This naive forecast shows one would have expected NGDP growth to have reached as much as 8 percent during the recovery before settling back down to its average. Instead we barely got over 3 percent growth. This is why NGDP has never caught back up to its pre-crisis trend path. 

Again, these two developments are, in my view, the real story behind the drop in trend inflation. And to be clear, I think both the Fed's unwillingness to allow temporary overshooting and the safe asset shortage problem have contributed to it. So this is a joint monetary-fiscal problem that has effectively created a monetary regime change.

So yes, we got a monetary regime change, but no it is not the one Christina Romer and most of us wanted.