Note to Fed: Get Out in Front of the Potential Debt Crisis.

The consequences of the U.S. government defaulting, even if for a few days, could be significant. The long-term effect is that the U.S. economy could lose some or all of its 'exorbitant privilege' which has allowed Americans for many years to live beyond their means. The short-term effect could be a major financial crisis as noted by Dick Bove over at FT Alphaville. Here is how he believe it could play out:

Money Market Mutual Funds
Should the United States government default virtually every money market mutual fund (MMMF) in the country would “break-the-buck” – i.e., be unable to pay investors 100 cents on every dollar invested. At present, MMMFs that do not actually earn enough money to pay back 100 cents on the dollar are subsidized by the fund management company. A Treasury default would make this virtually impossible and millions of Americans would lose billions of dollars.

Mutual Funds

The indentures of most bond and balanced mutual funds require that they immediately divest their holdings of defaulted securities. This could cause hundreds of billions in Treasuries to be sold immediately when the default was announced.

Depository Institutions
Let’s shift to another government document. This would be the FDIC’s aggregate balance sheet of the American banking industry... A reasonable estimate would be that the U.S. banking industry owns $1.85 trillion in government backed securities. It has $1.63 trillion in equity. If the Treasury and related securities were in default, one does not know what they would be worth. Assume a Latin American valuation of 10 to 20 cents on the dollar and an estimated $1.28 trillion in U.S. banking equity would be wiped out...In addition to the U.S. backed securities the banks own, they own an additional $1.27 trillion in other securities that would plunge in value... They have $7.73 trillion in loans which would also fall in value.

These developments would probably spill over into other markets. Such dire outcomes sound a lot like the concerns Fed Chairman Ben Bernanke had about the Eurozone Crisis back in 2011. Like now, I argued back then that Bernanke should get out in front of the Eurozone Crisis. Here is what I said:

So what can the Fed do? Here is a suggestion: the Fed could say if total current dollar spending begins to plummet because concerns about the financial system are causing investors to rapidly buy up safe money-like assets (time and saving accounts, money market accounts, treasuries, etc.) then the Fed would begin buying up less-safe and less-liquid assets until the investors' demand for money-like assets is satiated such that they return total current dollar spending to its previous level. The Fed would need to stress the "until" part means it would purchase as many trillions of dollars of assets as necessary to restore total current dollar spending. Since this  process would take place over time, the Fed would also want to set a target growth rate for where it wanted the level of total current dollar spending to go.    

If the above sounds reasonable to you, then you should be a fan of nominal GDP level targeting.  It is exactly what the U.S. economy needed in early 2008 when inflation expectations and velocity started falling.  And it is exactly what the  U.S. economy needs now.   

So if the Fed wants to get out in front of the potential debt crisis, one important step it could take is to announce a NGDP level target. The Fed's QE programs have been able to able to offset much of the fiscal drag over the past three years. A NGDP level target would step up the Fed's game and make it better able to deal with the fallout of debt default. It would not solve all problems--for example, the U.S. might face permanently higher risk premiums--but it at least could offset any drag it might create on aggregate nominal spending. Now would be a great time to act.

P.S. An interesting question raised by Jeffrey Frankel is if the default happens, will it create a financial crisis before or after October 17. 

More on George Bailey, QE, and the Shortage of Safe Assets

In my previous post I made the case that the Fed is not exacerbating the safe asset shortage problem. Rather, the Fed has actually prevented it from becoming far worse. Michael Darda, chief economist of MKM Partners, makes a great follow-up point in an email:

One thing that jumped into my mind when reading [your post] was the consistent tendency for the yields on safe assets to rise during “QE on” periods. We’ve now had three episodes of QE since 2009, and in each and every case, the 10-year yield has risen on net, only to fall when the Fed stopped too soon (after QE1 and QE2 came to a premature end, that is). This, I think, is a pretty airtight refutation that the Fed is somehow exacerbating the safe asset shortage; indeed, this alone suggests that QE is actually relieving it. And even with the recent pullback in rates, the 10-year yield is more than 100 bps above where it was before QE3 began (with the S&P 500 up 25% or so over the same timeframe). This, in my view, means it is working.

Ironically, one implication of this analysis is that the safe asset shortage problem exists, in part, because the Fed was not doing enough. Or at least, not doing it right. This a point I made in my last National Review article.

What George Bailey Can Teach Us About QE

Quantitative easing (QE) is a lot like George Bailey in the classic film It's a Wonderful Life. George was a man who began questioning his value to society. A number of cascading events--unfulfilled life dreams, a run on his bank, lost bank deposits, bank fraud charges--made it appear to hm that he was on balance a drag on his community. George decided it would be better for all if he 'tapered' or ended his life. Fortunately, an angel appeared at the last minute and revealed that despite his immediate problems, George's overall contributions to society were immense. Many lives were saved and changed because of his efforts. All that was needed to see this fact was a broader, longer perspective. George Bailey, in other words, was not doing the right counterfactual.

The same is true for skeptics of QE. Many point to the apparent flaws of the Fed's large scale asset purchases (LSAPs), but fail to step back and consider the counterfactual of what would have happened in their absence. This point is particularly poignant to those observers who claim the Fed's LSAPs of treasuries are particularly bad because they drain the financial system of safe assets. These critics note that these safe assets serve as collateral in the shadow banking system and thus facilitate transactions. Therefore, when the Fed increases its balance sheet it is actually restricting the funding capabilities of the shadow banking system and creating a drag on the economy. A growing number of smart people are making this point, including Izabella Kaminski, Tyler Cowen, Peter Stella, Arvind Krishnamurthy and Annette Vissing-Jorgensen, and Michael Woodford. I contend that while correct on the immediate effect of LSAPs, these critics like George Bailey are doing the wrong counterfactual. The right counterfactual is what would have happened had there been no QE2 and QE3 at all.

Before delving deeper into this counterfactual, I want to mention two other points about this critique. First, most of the safe asset shortage was created by factors other than the Fed's LSAPs. On the supply side, there was the destruction and subsequent anemic recovery of private-label safe assets as seen in this figure. On the demand side, the financial crisis and then a spate of subsequent bad economic news--Eurozone crisis, China slowdown concerns, debt limit talks, fiscal cliff talks--has kept the demand for safe asset elevated. Also, new regulatory requirements requiring banks to hold more safe assets is keeping safe asset demand elevated. 

Consequently, forces other than QE2 and QE3 have been driving much of the safe asset shortage. This can be seen in the figure below which shows the treasury general collateral repo rate and the Fed's share of marketable treasury securities. Note that the largest drop in the repo rate (reflecting the reduced supply and increased demand for treasuries collateral) occurred between late 2007 and early 2009, the very time the Fed was releasing treasury securities back into the market.

Second, even though the LSAPs do cause an immediate drain of safe assets, they potentially lead to more private safe asset creation. As I noted before:

The LSAPs, if done right, should raise expected economic growth going forward and cause asset prices to soar. This, in turn, would increase the current demand for and supply of financial intermediation. For example, AAA-rated corporations may issue more bonds to build up productive capacity in expectation of higher future sales growth. Financial firms, likewise, may start providing more loans as the improved economic outlook makes households and firms appear as better credit risks.

There is some evidence this is happening with QE2 and QE3. Even if these private safe assets are not used as collateral in the repo markets they will be used elsewhere to satiate liquidity demand. That, in turn, should free up more treasuries for use in the repo market. Both of these points are often overlooked by QE critics.

Now back to the counterfactual point. Are QE critics really making the same mistake as George Bailey? To answer that question, let's think through the counterfactual of no QE2 and QE3. First, assume the Fed's share of marketable treasuries was constant over this period. Also, assume that the shocks from the Eurozone crisis, China slowdown, debt limit and fiscal cliff talks still buffeted the U.S. economy during this time. What would have happened to the U.S. economy? Could the U.S. economy have been as resilient to these shocks had the Fed not been supporting it? If not, then imagine the mess in the financial system and what that would have done to the demand for safe assets. Repo markets, for example, would probably be facing an even larger collateral shortage. A reasonable counterfactual, then, is that the safe asset problem would be greater were it not for the Fed's QE programs. 

I took this idea to the data. I estimated a vector autoregression (VAR) over the 2003:1 to 2013:8 period and used it to create a counterfactual path for the 2010:10 to 2013:8 period.¹ This corresponds to the QE2 and Q3 periods. VARs are great for this type of exercise because one, they allow the variables in the model to interact and two, you can do dynamic forecast with them. The only twist here is that I did a conditional dynamic forecast. Specifically, I dynamically forecasted what would happen to employment, the stock market, PCE core inflation, and the repo rate conditional on (1) the Fed not increasing its share of marketable treasuries and (2) allowing the Eurozone crisis, China slowdown, and fiscal policy shocks to still affect the economy. For the latter, I used the actual, realized values of the economic policy uncertainty index over the forecasted period as a way to summarize and include these shocks in the VAR. The results can be seen in the figures below.

The first figure shows counterfactual path for the Fed's share of marketable treasuries used in the forecast.

The next figure shows what happens to the stock market. It declines over much of the period.

The following figure reports the counterfactual path for employment. Again, not a pretty picture.

This next figure shows that core PCE inflation stays around 1% and never recovers. So QE is inflationary, at least relative to where inflation would be in its absence.

Finally, this figure shows that the repo rates would have gone negative. Now this would not happen in practice because of the ZLB. But the VAR does not know the ZLB and simply forecasts based on estimated relationships. The fact, though, that it goes significantly negative is instructive. It indicates the repo markets would have faced even greater collateral shortages had the Fed not done QE2 and QE3.

Now we do not want to read too much into these results. They come from a forecasting model that is far from perfect. Still, they indicate that a proper counterfactual of the QE programs requires more than just narrowly looking at the immediate impact of LSAPs on the collateral asset supply. We do not want to be like George Bailey and do the wrong counterfactual. Neither should the Fed. Otherwise, it too may be tempted to pull the trigger and taper too soon.

My assessment is that QE2 and QE3 has done more to shore up the U.S. economy than many observers realize. We do not know how much worse the economy would be in their absence, but the analysis above suggests it could have been ugly. With that said, the QE programs have been flawed because of their ad-hoc, make-it-up-as-we-go-along approach that until recently was not tied to any explicit target. Tying the LSAP more firmly to conditional outcomes would do much to improve them. The more rule-like and predictable the better.  I think George Bailey would agree.

Update: Michael Darda provides some follow-up comments here.

¹The VAR was estimated with the Fed share of market treasuries, the log of SP500, the log of employment, the core PCE inflation rate, the repo rate, and the economic policy uncertainty index. Six lags were used on the monthly data. The results were generally robust to longer lag lengths, but due to limited data six lags were chosen. The conditional forecast was created by imposing fixed values for the Fed share and the uncertainty index as noted above.

National Review and AEI: Hotbed of Market Monetarism

While I was away from blogging, two places that kept the Market Monetarism torch burning were the National Review and the American Enterprise Institute. Not everyone at these institutions are fans of Market Monetarism, but National Review Senior Editor Ramesh Ponnuru and AEI columnist Jim Pethokoukis are and produced some great articles. These two individuals happen to be highly influential conservative thought leaders. Thanks to them we are making some inroads on the right. Below are some of the pieces they wrote.

Ramesh Ponnuru:

1. Will Obama Make the Fed Even Worse? 
2. Cause for Depression
3. Fed Should Target Spending Not Inflation

Jim Pethokoukis: 

1. Right on Quantitative Easing
2. Five Questions to Market Monetarists (including yours truly) Over Five Days
• Question #1 on Monday: “QE is doing nothing since banks are just sitting on the money. Look at the huge increase in excess reserves! What’s the point? How is this boosting growth, exactly?” 
• Question #2 on Tuesday: “Maybe the Fed is having a positive economic impact, but isn’t it just a sugar high, papering over or propping up a bad economy with easy money?”
• Question #3 on Wednesday: “Why hasn’t QE been inflationary? 
• Question #4 on Thursday: ”Does it matter if the Fed dials back its bond purchases if its balance sheet remains monstrously huge?
• Question #5 on Friday: "Isn't this all just a form of central planning?

If you are are not already, be sure to follow their work.

At Least the Fed Has An Inflation Target, Right?

Five years into the crisis and the Fed still has not adopted a nominal GDP level target. At least we can take solace in the fact that the Fed now has an explicit inflation target, right? After all, the Fed stated it was serious about its new 2% inflation target when announced in January, 2012:

The inflation rate over the longer run is primarily determined by monetary policy, and hence the Committee has the ability to specify a longer-run goal for inflation. The Committee judges that inflation at the rate of 2 percent, as measured by the annual change in the price index for personal consumption expenditures, is most consistent over the longer run with the Federal Reserve's statutory mandate. Communicating this inflation goal clearly to the public helps keep longer-term inflation expectations firmly anchored, thereby fostering price stability and enhancing the Committee's ability to promote maximum employment in the face of significant economic disturbances.

Now an inflation target can be problematic if there are large and frequent supply shocks, but if we are in a slump that is largely the result of demand shocks this target should be good news. It should hold the Fed's feet to the fire--more so than when it was implicitly targeting inflation--and force it to do all the wonderful things promised in the paragraph above.

So let's see how the Fed has done by its own standard of targeting 2% PCE core inflation:

This is not what the Fed promised with its new inflation target. Instead of gravitating around an average 2% inflation target, the Fed seems to have made 2% an upper bound. And the lower bound appears to be around 1%. This band seems to have been operational since the crisis began. It also appears that the Fed's purchases of treasury securities are closely tied to subsequent changes in the inflation rate as seen below. Maybe the apparent make-it-up-as-we-go-along nature of the QE programs was not so ad-hoc after all. Maybe they always have been tied to keeping PCE core inflation in this band.

Just this week Justin Wolfers noted that the PCE deflator declined this past quarter. He wondered how the Fed could allow this to happen if it had a 2% inflation target. The answer, it seems, is the Fed is targeting an inflation band with 2% as the upper bound.

This is a point Ryan Avent has been making for some time. Here he is back in April, 2012:

The Fed's second failure is to treat the 2% figure as a ceiling rather than a target...The Fed's preferred inflation measure—core PCE inflation—remains below 2%; core PCE was 1.9% year-on-year in February, in which month it increased at a 1.6% annual rate. Inflation expectations have been stable to falling since then.

Perhaps more telling, the Fed gives a range for projected inflation over the next three years with 2% as the upper extent. If the Fed does indeed have a symmetric approach to the target, as Mr Bernanke asserted yesterday, one would expect 2% to be at the middle of the range, not the top. This is particularly damning as the Fed's estimate of the natural rate of unemployment doesn't appear at all in the projected unemployment-rate range over the next three years; the closest the Fed comes to meeting that side of the mandate is in 2014, when the bottom end of the projected unemployment-rate range gets within 0.7 percentage points of the top end of the natural-rate range.

The Fed isn't just failing on the guideposts set by economists like Paul Krugman, Kenneth Rogoff, Greg Mankiw and, yes, Ben Bernanke. It's failing on the terms it sets for itself. Consistently.

So exactly what has changed with the Fed's new inflation target? Other than creating more confusion, nothing. And the Fed seems to be getting really good at creating confusion as evidenced by the no taper fiasco. This has to stop. We need monetary policy that will respond in a predictable, systematic way conditional on the state of the economy. Right now the Fed is not doing that.

Monetary Policy at the ZLB: Three Quasi-Natural Experiments

Can monetary policy still pack a punch at the zero lower bound (ZLB)? For Market Monetarists, the answer is an unequivocal yes. For others, the answer is less clear. Paul Krugman, for example, made the following comment recently on the efficacy of monetary policy during liquidity traps:

[T]he liquidity trap is real; conventional monetary policy, it turns out, can’t deal with really large negative shocks to demand. We can argue endlessly about whether unconventional monetary policy could do the trick, if only the Fed did it on a truly huge scale..

Krugman is right, this issue is contentious. It has been argued almost endlessly over the past five years. I submit, however, that over this time we have had several quasi-natural experiments on the effectiveness of monetary policy at the ZLB. These "experiments" along with an earlier one have shed some light on this issue.

The first quasi-natural experiment has been happening over the course of this year. It is based on the observation that monetary policy is being tried to varying degrees among the three largest economies in the world. Specifically, monetary policy in Japan has been more aggressive than in the United States which, in turn, has had more aggressive monetary policy than the Eurozone.¹ These economies also have short-term interest rates near zero percent. This makes for a great experiment on the efficacy of monetary policy at the ZLB.

So what have these monetary policy differences yielded? The chart below answers the question in terms of real GDP growth through the first half of 2013:

The outcome seems very clear: when really tried, monetary policy can be very effective at the ZLB. Now fiscal policy is at work too, but for this period the main policy change in Japan has been monetary policy. And according to the IMF Fiscal Monitor, the tightening of fiscal policy over 2013 has been sharper in the United States than in the Eurozone. Yichang Wang illustrates this latter point nicely in this figure. So that leaves the variation in real GDP growth being closely tied to the variation in monetary policy. Chalk one up for the efficacy of monetary policy at the ZLB.

The second quasi-natural experiment has been running since 2010 in the United States. Over this period the cyclically-adjusted or structural budget balance as a percent of potential GDP has been shrinking. This is the best measure of the stance of fiscal policy, as noted by Paul Krugman:

[M]easuring austerity is tricky. You can’t just use budget surpluses or deficits, because these are affected by the state of the economy. You can — and I often have — use “cyclically adjusted” budget balances, which are supposed to take account of this effect. This is better; however, these numbers depend on estimates of potential output, which themselves seem to be affected by business cycle developments. So the best measure, arguably, would look directly at policy changes. And it turns out that the IMF Fiscal Monitor provides us with those estimates, as a share of potential GDP... 

Below is the IMF's measure of both the overall and primary structural budget balance for all levels of government:

So what is the implication of this figure? First, it shows that independent of business cycle influences fiscal policy has been tightening since 2010. It has gone from an overall deficit of 8.5% in 2010 to an expected one of about 4.6% in 2013. Stated differently, the above reduction in the general budget deficit is not the government endogenously adjusting its balance sheet in response to improvements in the private sector's balance sheet. Rather, it is the consequence of explicit policy choices to sharply tighten fiscal policy. 

So what have these three years of fiscal policy tightening done to aggregate demand over this time? Apparently nothing as seen in the figure below:

So what explains this development? How is it that fiscal policy tightening in conjunction with the Eurozone shocks, the China slowdown shocks, and other negative shocks has not slowed down aggregate demand growth? The answer is that Fed policy has effectively offset the effect of the fiscal austerity and the other shocks. This is another great quasi-natural experiment that demonstrates the effectiveness of monetary policy even with interest rates close to zero percent. Chalk another one up for the efficacy of monetary policy at the ZLB.

Of course, this remarkable stabilization of U.S. aggregate demand growth by the Fed has been far from adequate in terms of restoring full employment. It is, therefore, ultimately frustrating to watch. For it speaks to both the power and shortcomings of current Fed policy.

While these recent quasi-natural experiments on the efficacy of monetary policy at the ZLB are informative, an even more telling one can be found in the 1930s. This is the quasi-natural experiment of advanced economies going off the gold standard. As is well known, the interwar gold standard was flawed and played a key role in causing the Great Depression in the early 1930s. The countries involved were in a slump and their interest rates were near zero percent. Yet, as Eichengreen (1992) notes, the quicker a country abandoned the gold standard the quicker it experienced a robust recovery.

This cross-country, quasi-natural experiment of the efficacy of monetary policy at the ZLB should give any monetary skeptic pause. Christina Romer notes that in the case of the U.S. economy this recovery was almost entirely the consequence of easing monetary conditions. Fiscal policy played little role.

These three quasi-natural experiments indicate that there is much monetary policy can do at the ZLB. If so, the key issue is why central banks did not do more over the past three years to shore up the recovery.

¹In more precise terms, the Bank of Japan has signaled more definitely than the Federal Reserve a permanently higher future monetary base level relative to the expected real demand for it. The Fed, in turn, has signaled the same relative to the ECB.

Further Ossification of the Zero Lower Bound?

This is an email exchange I had with Miles Kimball on the Fed's new fixed rate, full allotment, reverse repo. We thought it was worth sharing with our readers. As noted in the email, I plan to do a follow up blog post that further examines the macroeconomic implications of this this new Fed tool. My discussion with Miles, though, gets to core of my concerns about the Fed's reverse repo. Thanks to Cardiff Garcia and Izabella Kaminski at FT Alphaville for helping clarify this issue. This is cross listed over at Mile's blog, Confessions of a Supply-Side Liberal.

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David: I have been meaning to contact you.  I am about to start blogging again and one of the issues I want to raise is the implication of the Fed introducing its fixed rate, full allotment, reverse repo.  I understand the point that it will help with the collateral shortage problem in repo markets—though I think this point ignores the counterfactual of what would happened to repo markets had their been no QE—but I also see it as further cementing the ZLB.  It, along with the IOR, will effectively create a floor on short-term interest rates given the Fed’s preferences to shore up money markets.  While this may be a nice short-term palliative, I see it as creating problems in future recessions if Fed preferences for money markets do not change.  This particularly seems problematic in light of what you have written about creating negative interest rates with e-money.  Here is a twitter exchange with the folks at FTAlphaville on this issue.

Does this critique make sense? If I am missing something here please let me know.

Miles: Thanks for your kind tweet today!

I confess I don’t see the issue. If the Fed has a reverse repo rate, the Fed can lower that too, when needed. The key is that when the repo rate is introduced, it should be made clear that it might potentially go negative, and have the machinery for that in place.  

In seminars on electronic money, I say that the Fed should move 4 interest rates in tandem:

    1. fed funds rate

    2. discount rate

    3. interest rate on reserves (no longer on just excess reserves when it is negative)

    4. paper currency interest rate

This would add a 5th:

     5. reverse repo rate

I also emphasize in seminars that lowering 1—3 while keeping 4 the same leads to unnatural spreads, and these unnatural spreads could, in fact, be worrisome for financial markets. On the other hand, I wouldn’t want to discourage lowering 1—3, since I think it is a big step towards lowering 1—4.  (Politically, the negative rates are the biggest deal, and the technical stuff to let the paper currency interest rate decline is more manageable politically once one has already taken the political hit from 1—3 going negative.)  If all four interest rates—or now all five—are lowered in tandem, spreads are normal, and only nominal illusion and troubles lowering nominal wages are of concern. 

In sum, if a reverse repo rate is introduced AND it is explicitly said at the time that it could go negative, that seems to me a good thing rather than a bad thing. But even if it is not explicitly said that it could go negative, I don’t see why that would be hard in the context of making 1—3 go negative, say. It is not like Japanese postal saving giving zero interest rates, where another institution is involved; all the rates are set by the Fed and it would only seem natural to lower the reverse repo rate if the others are lowered.  

Am I missing something? 

One side note: I confess that in a blog post about this, I would value highly a very detailed explanation of how the repo markets work, and what was going on with the negative interest rates in the repo market that you talked about here. What would be ideal would be an explanation understandable by a bright undergraduate with no experience in financial markets. Then maybe I can understand it, too!

In that context, the main thing to say is that the Fed should not be using the reverse repo rate to raise interest rates, when it is trying to keep other interest rates as low as possible. If the current repo rate is negative, the Fed should not raise that rate to zero. If the strains caused by abnormal spreads tempt them to do so, that is actually an argument for lowering the paper currency interest rate instead. Note the very important point that a modest lowering of the paper currency interest rate operative for financial firms can be achieved by a modest time-varying paper currency deposit charge when banks want to deposit paper currency with the Fed, without any other institutional change. (Because of the substantial transactions costs involved in taking someone to court, legal tender issues shouldn’t arise until paper currencies are several hundred basis points below zero, and in any case are manageable. Adjustments in how vault cash applies to reserve requirements are easy to make, if needed.) It would be great if this could be done in a somewhat quiet, technical-seeming way at this point. With that in place, it would be clearer that the interest rate on reserves (IOR) could be lowered.    

David: Thanks Miles. No, I agree that introducing the IOR and the reverse repo in principle does not prevent the Fed from making rates go negative. (It may even make it easier to push rates negative since it has now has greater influence over more markets.)  My concern is that the reason—at least what I have seen—for doing IOR and now the reverse repo is to help the interbank and repo markets.  And in practice that means keeping these rates in these markets positive. For example, the reverse repo seems geared toward helping the collateral-starved repo market by reselling to it the much desired treasuries.  But this would keep the repo rate up, or least keep it from falling. 

So it is not the technical capability of the IOR and reverse repo that concerns me, but how it is being used.  If this pattern continues, it seems the Fed will be further cementing the ZLB.

Miles: I think this is the unnatural spreads problem. As long as the paper currency interest rate is kept at zero, I think there is a genuine tension between wanting to keep normal spreads and wanting to keep interest rates down. Of course, QE is making other spreads unnaturally small. So it is a matter of being concerned about certain spreads. My image is not of cementing the zero lower bound, but adding a cushion to the zero lower bound to keep spreads from getting too thin. To the extent it is felt that that cushion is necessary to keep certain spreads from getting too thin, it makes the zero lower bound tighter than it otherwise would be. But the tension is all coming from the fixed paper currency interest rate.

I feel there can be legitimate disagreements about how much to worry about making certain spreads that are critical for certain financial institutions extra-thin and wanting to keep interest rates low. But what there should be no legitimate disagreement about (but of course, in fact there is plenty of disagreement about) is about the virtues of lowering all interest rates in tandem, including the paper currency interest rate. My UK friends Tomas Hirst and Frances Coppola have not fully come around to my view that with normal spreads, financial institutions will be fine even with negative interest rates. (See the links on their names, and my many discussions with them chronicled on my electronic money sub-blog.) But I think that is basically right, at least given a little advance warning of negative rates in order to adjust the nominal illusion bits of their business models. The strains on financial institutions from lowering all interest rates but the paper currency interest rate should not be extrapolated to a situation where all interest rates are lowered, including the paper currency interest rate.

David: Great point. If all interest rates are lowered in tandem so that spreads are relatively stable, then negative interest rates should not be a problem for financial firms.  Their net interest margins will be stable too and financial intermediation should continue.  That is a neat way to frame this issue.