Showing posts with label Academic Articles. Show all posts
Showing posts with label Academic Articles. Show all posts

Sunday, December 17, 2023

Bond risk premiums -- certainty found and lost again

This is a second post from a set of comments I gave at the NBER Asset Pricing conference in early November at Stanford.  Conference agenda hereMy full slides here. First post here, on new-Keynesian models

I  commented on "Downward Nominal Rigidities and Bond Premia" by François Gourio  and Phuong Ngo. The paper was about bond premiums. Commenting made me realize that I thought I understood the issue, and now I realize I don't at all. Understanding term premiums still seems a fruitful area of research after all these years.  

I thought I understood risk premiums

The term premium question is, do you earn more money on average holding long term bonds or short-term bonds? Related, is the yield curve on average upward or downward sloping? Should an investor hold long or short term bonds? 

Friday, December 8, 2023

New-Keynesian models, a puzzle of scientific sociology

This post is from a set of comments I gave at the NBER Asset Pricing conference in early November at Stanford.  Conference agenda here. My full slides here. There was video, but sadly I took too long to write this post and the NBER took down the conference video. 

I was asked to comment on "Downward Nominal Rigidities and Bond Premia" by François Gourio  and Phuong Ngo. It's a very nice clean paper, so all I could think to do as discussant is praise it, then move on to bigger issues. These are really comments about whole literatures, not about one paper. One can admire the play but complain about the game. 

The paper implements a version of Bob Lucas' 1973 "International evidence" observation. Prices are less sticky in high inflation countries. The Phillips curve more vertical. Output is less affected by inflation. The Calvo fairy visits every night in Argentina. To Lucas, high inflation comes with variable inflation, so people understand that price changes are mostly aggregate not relative prices, and ignore them. Gourio and Ngo use a new-Keynesian model with downwardly sticky prices and wages to express the idea.  When inflation is low, we're more often in the more-sticky regime. They use this idea in a model of bond risk premia. Times of low inflation lead to more correlation of inflation and output, and so a different correlation of nominal bond returns with the discount factor, and a different term premium. 

I made two points, first about bond premiums and second about new-Keynesian models. Only the latter for this post. 

This paper, like hundreds before it, adds a few ingredients on top of a standard textbook new-Keynesian model. But that textbook model has deep structural problems. There are known ways to fix the problems. Yet we continually build on the standard model, rather than incorporate known ways or find new ways to fix its underlying problems. 

Problem 1: The sign is "wrong" or at least unconventional.

Monday, December 4, 2023

FTPL news: discount and Economist list

 


Just in time for the holidays, the perfect stocking stuffer -- if you have really big stockings. 30% discount on Fiscal Theory of the Price Level until June 30 2024. 

And Fiscal Theory makes the Economist's list of best books for 2023





Friday, October 13, 2023

Heterogeneous Agent Fiscal Theory

Today, I'll add an entry to my occasional reviews of interesting academic papers. The paper: "Price Level and Inflation Dynamics in Heterogeneous Agent Economies," by Greg Kaplan, Georgios Nikolakoudis and Gianluca Violante. 

One of the many reasons I am excited about this paper is that it unites fiscal theory of the price level with heterogeneous agent economics. And it shows how heterogeneity matters. There has been a lot of work on "heterogeneous agent new-Keynesian" models (HANK). This paper inaugurates heterogeneous agent fiscal theory models. Let's call them HAFT. 

Monday, August 28, 2023

Interest rates and inflation part 3: Theory

This post takes up from two previous posts (part 1;  part 2), asking just what do we (we economists) really know about how interest rates affect inflation. Today, what does contemporary economic theory say? 

As you may recall, the standard story says that the Fed raises interest rates; inflation (and expected inflation) don't immediately jump up, so real interest rates rise; with some lag, higher real interest rates push down employment and output (IS); with some more lag, the softer economy leads to lower prices and wages (Phillips curve). So higher interest rates lower future inflation, albeit with "long and variable lags." 

Higher interest rates -> (lag) lower output, employment -> (lag) lower inflation. 

In part 1, we saw that it's not easy to see that story in the data. In part 2, we saw that half a century of formal empirical work also leaves that conclusion on very shaky ground. 

As they say at the University of Chicago, "Well, so much for the real world, how does it work in theory?" That is an important question. We never really believe things we don't have a theory for, and for good reason. So, today, let's look at what modern theory has to say about this question. And they are not unrelated questions. Theory has been trying to replicate this story for decades. 

The answer: Modern (anything post 1972) theory really does not support this idea. The standard new-Keynesian model does not produce anything like the standard story.  Models that modify that simple model to achieve something like result of the standard story do so with a long list of complex ingredients. The new ingredients are not just sufficient, they are (apparently) necessary to produce the desired dynamic pattern. Even these models do not  implement the verbal logic above. If the pattern that high interest rates lower inflation over a few years is true, it is by a completely different mechanism than the story tells. 

I conclude that we don't have a simple economic model that produces the standard belief. ("Simple" and "economic" are important qualifiers.) 

The simple new-Keynesian model 

Thursday, August 10, 2023

Interest rates and inflation part 2: Losing faith in VARs

(This post continues part 1 which just looked at the data. Part 3 on theory is here

When the Fed raises interest rates, how does inflation respond? Are there "long and variable lags" to inflation and output?  

There is a standard story: The Fed raises interest rates; inflation is sticky so real interest rates (interest rate - inflation) rise; higher real interest rates lower output and employment; the softer economy pushes inflation down. Each of these is a lagged effect. But despite 40 years of effort, theory struggles to substantiate that story (next post), it's had to see in the data (last post), and the empirical work is ephemeral -- this post.  

The vector autoregression and related local projection are today the standard empirical tools to address how monetary policy affects the economy, and have been since Chris Sims' great work in the 1970s. (See Larry Christiano's review.) 

I am losing faith in the method and results. We need to find new ways to learn about the effects of monetary policy. This post expands on some thoughts on this topic in "Expectations and the Neutrality of Interest Rates," several of my papers from the 1990s* and excellent recent reviews from Valerie Ramey and  Emi Nakamura and Jón Steinsson, who  eloquently summarize the hard identification and computation troubles of contemporary empirical work.

Maybe popular wisdom is right, and economics just has to catch up. Perhaps we will. But a popular belief that does not have solid scientific theory and empirical backing, despite a 40 year effort for models and data that will provide the desired answer, must be a bit less trustworthy than one that does have such foundations. Practical people should consider that the Fed may be less powerful than traditionally thought, and that its interest rate policy has different effects than commonly thought. Whether and under what conditions high interest rates lower inflation, whether they do so with long and variable but nonetheless predictable and exploitable lags, is much less certain than you think. 

Saturday, August 5, 2023

Interest rates and inflation -- part 1

Today I begin a three part series exploring interest rates and inflation. (Part 2 empirical work, Part 3 theory) 

How does the Fed influence inflation? Is the recent easing of inflation due to Fed policy, or happening on its own? To what extent should we look just to the Fed to bring inflation under control going forward? 

The standard story: The Fed raises the interest rate. Inflation is somewhat sticky. (Inflation is sticky. This is important later.) Thus the real interest rate also rises. The higher real interest rate softens the economy. And a softer economy slowly lowers inflation. The effect happens with "long and variables lags," so a higher interest rate today lowers inflation only a year or so from now. 

interest rate -> (lag) softer economy -> (lag) inflation declines

This is a natural heir to the view Milton Friedman propounded in his 1968 AEA presidential address, updated with interest rates in place of money growth. A good recent example is Christina and David Romer's paper underlying her AEA presidential address, which concludes of current events that as a result of the Fed's recent interest-rate increases, "one would expect substantial negative impacts on real GDP and inflation in 2023 and 2024."

This story is passed around like well worn truth. However, we'll see that it's actually much less founded than you may think. Today, I'll look at simple facts. In my next post, I'll look at current empirical work, and we'll find that support for the standard view is much weaker than you might think. Then, I'll look at theory. We'll find that contemporary theory (i.e. for the last 30 years) is strained to come up with anything like the standard view. 


Here's the history of interest rates and inflation. We're looking to see if high real interest rates push inflation down. 

Tuesday, July 11, 2023

New York Times on HANK, and questions

By the standards of mainstream media coverage of technical economics, Peter Coy's coverage of HANK (Heterogeneous Agent New Keynesian) models in the New York Times was actually pretty good. 

1) Representative agents and distributions. 

Yes, it starts with the usual misunderstanding about "representative agents," that models assume we are all the same. Some of this is the standard journalist's response to all economic models: we have simplified the assumptions, we need more general assumptions. They don't understand that the genius of economic theory lies precisely in finding simplified but tractable assumptions that tell the main story. Progress never comes from putting more ingredients and stirring the pot to see what comes out. (I mean you, third year graduate students looking for a thesis topic.) 

But in this case many economists are also confused on this issue. I've been to quite a few HANK seminars in which prominent academics waste 10 minutes or so dumping on the "assumption that everyone is identical." 

There is a beautiful old theorem, called the "social welfare function." (I learned this in graduate school in fall 1979, from Hal Varian's excellent textbook.) People can have almost arbitrarily different preferences (utility functions), incomes and shocks, companies can have almost arbitrarily different characteristics (production functions),  yet the aggregate economy behaves as if there is a single representative consumer and representative firm. The equilibrium path of aggregate consumption, output,  investment, employment, and the prices and interest rates of that equilibrium are the same as those of an economy where everyone and every firm is the same, with a "representative agent" consumption function and "representative firm" production function.  Moreover, the representative agent utility function and representative firm production function need not look anything like those of any particular individual person and firm. If I have power utility and you have quadratic utility, the economy behaves as if there is a single consumer with something in between. 

Defining the job of macroeconomics to understand the movement over time of aggregates -- how do GDP, consumption, investment, employment, price level, interest rates, stock prices etc. move over time, and how do policies affect those movements -- macroeconomics can ignore microeconomics. (We'll get back to that definition in a moment.) 

Friday, June 9, 2023

The Fed and the Phillips curve

I just finished a new draft of "Expectations and the neutrality of interest rates," which includes some ruminations on inflation that may be of interest to blog readers. 

A central point of the paper is to ask whether and how higher interest rates lower inflation, without a change in fiscal policy. That's intellectually interesting, answering what the Fed can do on its own. It's also a relevant policy question. If the Fed raises rates, that raises interest costs on the debt. What if Congress refuses to tighten to pay those higher interest costs? Well, to avoid a transversality condition violation (debt that grows forever) we get more inflation, to devalue outstanding debt. That's a hard nut to avoid.  

But my point today is some intuition questions that come along the way. An implicit point: The math of today's macro is actually pretty easy. Telling the story behind the math, interpreting the math, making it useful for policy, is much harder. 

1. The Phillips curve

The Phillips curve is central to how the Fed and most policy analysts think about inflation. In words, inflation is related to expected future inflation and by some measure if economic tightness, factor \(x\). In equations, \[ \pi_t = E_t \pi_{t+1} + \kappa x_t.\] Here \(x_t\) represents the output gap (how much output is above or below potential output), measures of labor market tightness like unemployment (with a negative sign), or labor costs. (Fed Governor Chris Waller has a great speech on the Phillips curve, with a nice short clear explanation. There are lots of academic explanations of course, but this is how a sharp sitting member of the FOMC thinks, which is what we want to understand. BTW, Waller gave an even better speech on climate and the Fed. Go Chris!)  

So how does the Fed change inflation? In most analysis, the Fed raises interest rates; higher interest rates cool down the economy lowering factor x; that pushes inflation down. But does the equation really say that? 

Wednesday, May 24, 2023

Hoover Monetary Policy Conference Videos

The videos from the Hoover Monetary Policy Conference are now online here.  See my previous post for a summary of the conference. 

The big picture is now clearer to me. Phil Jefferson rightly asked, what do you mean off track? Monetary policy is doing fine. Interest rates are, in his view, where they should be. He argued the case well. 

But now I have an answer: The Fed has had three significant institutional failures: 1) Its inflation target is 2%, yet inflation exploded to 8%. The Fed did not forecast it, and did not see it even as it was happening. (Nor did many other forecasters, pointing to deeper conceptual problems.) 2) In the SVB and subsequent mess, the Fed's regulatory apparatus did not see or do anything about plain vanilla interest-rate risk combined with uninsured deposits. 3) I add a third, that nobody else seems to complain about: In 2020 starting with treasury markets, moving on to money market funds, state and local financing,  and then an astonishing "whatever it takes" that corporate bond prices shall not fall, the Fed already revealed that the Dodd-Frank machinery was broken. (Will commercial real estate be next?) 

Yet there is very little appetite for self-examination or even external examination. How did a good institution, filled with good, honest, smart and devoted public servants fail so badly? That's not "off-track" that's a derailment. 

Well, two sessions at the conference begin to ask those questions, and the others aimed at the same issues. Hopefully they will prod the Fed to do so as well, or at least to be interested in other's answers to those questions. 

(My minor contributions: on why the Taylor rule is important here, where I think I did a pretty good job; and comments on why inflation forecasts went so wrong at  1:00:16 here.)

Bradley Prize speech, video, and thanks

The videos and speeches of the Bradley prize winners are up. My video here (Grumpy in a tux!), also the speech which I reproduce below. All the videos and speeches here (Betsy DeVos and Nina Shea) My previous interview with Rick Graeber, head of the Bradley foundation. 

Bradley also made a nice introduction video with photos from my childhood and early career. (A link here to the introduction video and speech together.) And to avoid us spending all our talks on thanking people, they had us write out a separate thanks. That seems not to be up yet, but I include mine below. I am very thankful, humbled to be included in such august company, and not so boorish that I would not have spent my whole talk without mentioning that, absent the separate opportunity to say so. 

Bradley prize remarks (i.e. condense three decades of policy writing into 10 minutes): 

Creeping stagnation ought to be recognized as the central economic issue of our time. Economic growth since 2000 has fallen almost by half compared with the last half of the 20th Century. The average American’s income is already a quarter less than under the previous trend. If this trend continues, lost growth in fifty years will total three times today’s economy. No economic issue — inflation, recession, trade, climate, income diversity — comes close to such numbers.

Growth is not just more stuff, it’s vastly better goods and services; it’s health, environment, education, and culture; it’s defense, social programs, and repaying government debt.

Why are we stagnating? In my view, the answer is simple: America has the people, the ideas, and the investment capital to grow. We just can’t get the permits. We are a great Gulliver, tied down by miles of Lilliputian red tape.  

Wednesday, May 17, 2023

Bob Lucas and his papers

My first post described a few anecdotes about what a warm person Bob Lucas was, and such a great colleague. Here I describe a little bit of his intellectual influence, in a form that is I hope accessible to average people.

The “rational expectations” revolution that brought down Keynesianism in the 1970s was really much larger than that. It was really the “general equilibrium” revolution. 

Macroeconomics until 1970 was sharply different from regular microeconomics. Economics is all about “models,” complete toy economies that we construct via equations and in computer programs. You can’t keep track of everything in even the most beautiful prose. Microeconomic models, and “general equilibrium” as that term was used at the time, wrote down how people behave — how they decide what to buy, how hard to work, whether to save, etc.. Then it similarly described how companies behave and how government behaves. Set this in motion and see where it all settles down; what prices and quantities result. 

Tuesday, May 16, 2023

Hoover Monetary Policy Conference

Friday May 12 we had the annual Hoover monetary policy conference. Hoover twitter stream here.  Conference webpage and schedule here (update 5/24 now contains videos.) As before, the talks, panels, and comments will eventually be written and published. 

The Fed has experienced two dramatic institutional failures: Inflation peaking at 8%, and a rash of bank failures. There were panels focused on each, and much surrounding discussion.  

Monday, May 15, 2023

Bob Lucas

I just got the sad news that Bob Lucas has passed away. He was truly a giant among economists, and a wonderful warm person. 

I will only pass on three remembrances that others will not likely mention. 

Bob was incredibly welcoming to me, a young brash and fairly untutored young economist from Berkeley.  

In the fall of 1985 I gave what was no doubt the most disastrous first seminar by a new assistant professor in the Department's history. It was something about random walks and real business cycles, and was going nowhere. Bob stopped by my office, and expressed doubt about this random walk stuff. He said, if you look at longer and longer horizons, GNP volatility goes down. At least I had the wit to recognize what had just been handed to me on a silver platter, dropped everything and wrote the "Random walk in GNP," my first big paper. Without that, I doubt I would be where I am today. Thank you Bob.  He and Nancy were kind to us socially as well. 

The first Lucas paper that I recall reading, while I was still at Berkeley, was his review of a report to the OECD.  I don't think anyone else writing about Bob will mention this masterpiece. If you get annoyed by policy blather, read this article. Reading it as a grad student, I loved the way he sliced through loose prose like warm butter. No BS with Bob. Only clear thinking please. I mentioned it later, and he laughed saying he wrote it in a bad mood because he was getting divorced. Like "After Keynesian Macroeconomics," Bob could wield a pen. 

Much later,  I attended a revelatory money workshop. Bob presented an early version of, I think, "Ideas and growth."  In the model, people have ideas, and bump into each other randomly and share ideas. Questioner after questioner complained that there wasn't any economics in the model. Why not put in some incentive for people to bump in to each other, or something non mechanical. Time after time, Bob answered each suggestion that he had tried it, but it didn't make much difference to the outcome, so he stripped it out of the model. Clearly, he had been playing with this model over a year, working to eliminate  needless ingredients, not to add more generality. It's great to see the production function at work. 

Bob is known as a theorist, but he had a great handle on empirical work as well. His Carnegie Rochester money demand paper basically reinvented cointegration, and saw clearly what dozens of others missed. "Mechanics of economic development" starts by putting together facts. "International evidence on inflation-output tradeoffs" 1973 makes one stunning graph. And more. 

There is so much to say about Bob the great economist, superb colleague and tremendous human being, but I will stop here for now. RIP Bob. And thank you. 

Update:

Ben Moll has a lovely twitter thread about Bob as a thesis adviser. Bob covered Ben's thesis draft with useful comments. Bob read my early papers and did the same thing. This encouraged a culture of comments. Though a young assistant professor, I took it as a duty to write comments on Bob's papers! And some of them actually helped. This was the culture of the economics department in the 1980s, not common. Bob helped quite a few people and JPE authors to see what their papers were really about, making dramatic improvements.  

The outpouring on twitter is remarkable. More remarkable, here is a man for whom we could celebrate every single paper as pathbreaking. Yet the outpouring is all about his wonderful personal qualities. 

A correspondent reminds me of one last story. Bob's divorce agreement specified half of his Nobel prize, which he paid. Asked  by a reporter if he had regrets, he answered "A deal's a deal." 

Next post, focused on intellectual contributions. 

Thursday, April 20, 2023

How do interest rates lower inflation?

 

A few days ago I gave a short talk on the subject. I was partly inspired by a little comment made at a seminar, roughly "of course we all know that if prices are sticky, higher nominal rates raise higher real rates, that lowers aggregate demand and lowers inflation." Maybe we "know" that, but it's not as readily present in our models as we think. This also crystallizes some work in the ongoing "Expectations and the neutrality of interest rates" project. 

The equations are the utterly standard new-Keynesian model. The last equation tracks the evolution of the real value of the debt, which is usually in the footnotes of that model. 

OK, top right, the standard result. There is a positive but temporary shock to the monetary policy rule, u. Interest rates go up and then slowly revert. Inflation goes down. Hooray. (Output also goes down, as the Phillips Curve insists.) 

The next graph should give you pause on just how you interpreted the first one. What if the interest rate goes up persistently? Inflation rises, suddenly and completely matching the rise in interest rate! Yet prices are quite sticky -- k = 0.1 here. Here I drove the persistence all the way to 1, but that's not crucial. With any persistence above 0.75, higher interest rates give rise to higher inflation. 

What's going on? Prices are sticky, but inflation is not sticky. In the Calvo model only a few firms can change price in any instant, but they change by a large amount, so the rate of inflation can jump up instantly just as it does. I think a lot of intuition wants inflation to be sticky, so that inflation can slowly pick up after a shock. That's how it seems to work in the world, but sticky prices do not deliver that result. Hence, the real interest rate doesn't change at all in response to this persistent rise in nominal interest rates.  Now maybe inflation is sticky, costs apply to the derivative not the level, but absolutely none of the immense literature on price stickiness considers that possibility or how in the world it might be true, at least as far as I know. Let me know if I'm wrong. At a minimum, I hope I have started to undermine your faith that we all have easy textbook models in which higher interest rates reliably lower inflation. 

(Yes, the shock is negative. Look at the Taylor rule. This happens a lot in these models, another reason you might worry. The shock can go in a different direction from observed interest rates.) 

Panel 3 lowers the persistence of the shock to a cleverly chosen 0.75. Now (with sigma=1, kappa=0.1, phi= 1.2), inflation now moves with no change in interest rate at all.  The Fed merely announces the shock and inflation jumps all on its own. I call this "equilibrium selection policy" or "open mouth policy." You can regard this as a feature or a bug. If you believe this model, the Fed can move inflation just by making speeches! You can regard this as powerful "forward guidance." Or you can regard it as nuts. In any case, if you thought that the Fed's mechanism for lowering inflation is to raise nominal interest rates, inflation is sticky, real rates rise, output falls and inflation falls, well here is another case in which the standard model says something else entirely. 

Panel 4 is of course my main hobby horse these days. I tee up the question in Panel 1 with the red line. In that panel, the nominal interest are is higher than the expected inflation rate. The real interest rate is positive. The costs of servicing the debt have risen. That's a serious effect nowadays. With 100% debt/GDP each 1% higher real rate is 1% of GDP more deficit, $250 billion dollars per year. Somebody has to pay that sooner or later. This "monetary policy" comes with a fiscal tightening. You'll see that in the footnotes of good new-Keynesian models: lump sum taxes come along to pay higher interest costs on the debt. 

Now imagine Jay Powell comes knocking to Congress in the middle of a knock-down drag-out fight over spending and the debt limit, and says "oh, we're going to raise rates 4 percentage points. We need you to raise taxes or cut spending by $1 trillion to pay those extra interest costs on the debt." A laugh might be the polite answer. 

So, in the last graph, I ask, what happens if the Fed raises interest rates and fiscal policy refuses to raise taxes or cut spending? In the new-Keynesian model there is not a 1-1 mapping between the shock (u) process and interest rates. Many different u produce the same i. So, I ask the model, "choose a u process that produces exactly the same interest rate as in the top left panel,  but needs no additional fiscal surpluses." Declines in interest costs of the debt (inflation above interest rates) and devaluation of debt by period 1 inflation must match rises in interest costs on the debt (inflation below interest rates). The bottom right panel gives the answer to this question. 

Review: Same interest rate, no fiscal help? Inflation rises. In this very standard new-Keynesian model,  higher interest rates without a concurrent fiscal tightening raise inflation, immediately and persistently. 

Fans will know of the long-term debt extension that solves this problem, and I've plugged that solution before (see the "Expectations" paper above).

The point today: The statement that we have easy simple well understood textbook models, that capture the standard intuition -- higher nominal rates with sticky prices mean higher real rates, those lower output and lower inflation -- is simply not true. The standard model behaves very differently than you think it does. It's amazing how after 30 years of playing with these simple equations, verbal intuition and the equations remain so far apart. 

The last two bullet points emphasize two other aspects of the intuition vs model separation. Notice that even in the top left graph, higher interest rates (and lower output) come with rising inflation. At best the higher rate causes a sudden jump down in inflation -- prices, not inflation, are sticky even in the top left graph -- but then inflation steadily rises. Not even in the top left graph do higher rates send future inflation lower than current inflation. Widespread intuition goes the other way. 

In all this theorizing, the Phillips Curve strikes me as the weak link. The Fed and common intuition make the Phillips Curve causal: higher rates cause lower output cause lower inflation. The original Phillips Curve was just a correlation, and Lucas 1972 thought of causality the other way: higher inflation fools people temporarily to producing more. 


 

Here is the Phillips curve (unemployment x axis, inflation y axis) from 2012 through last month. The dots on the lower branch are the pre-covid curve, "flat" as common wisdom proclaimed. Inflation was still 2% with unemployment 3.5% on the eve of the pandemic. The upper branch is the more recent experience. 

I think this plot makes some sense of the Fed's colossal failure to see inflation coming, or to perceive it once the dragon was inside the outer wall and breathing fire at the inner gate. If you believe in a Phillips Curve, causal from unemployment (or "labor market conditions") to inflation, and you last saw 3.5% unemployment with 2% inflation in February 2021, the 6% unemployment of March 2021 is going to make you totally ignore any inflation blips that come along. Surely, until we get well past 3.5% unemployment again, there's nothing to worry about. Well, that was wrong. The curve "shifted" if there is a curve at all. 

But what to put in its place? Good question. 

Update:

Lots of commenters and correspondents want other Phillips Curves. I've been influenced by a number of papers, especially "New Pricing Models, Same Old Phillips Curves?" by Adrien Auclert, Rodolfo Rigato, Matthew Rognlie, and Ludwig Straub, and "Price Rigidity: Microeconomic Evidence and Macroeconomic Implications" by Emi Nakamura and  Jón Steinsson, that lots of different micro foundations all end up looking about the same. Both are great papers. Adding lags seems easy, but it's not that simple unless you overturn the forward looking eigenvalues of the system; "Expectations and the neutrality of interest rates" goes on in that way. Adding a lag without changing the system eigenvalue doesn't work. 

Saturday, March 4, 2023

Economic Journal Home Bias

Home Bias in Economics Journals is an interesting new paper by Dirk Bethmann, Felix Bransch, Michael Kvasnicka, and Abdolkarim Sadrieh (via Marginal Revolution).

...Researchers from Harvard, but also nearby Massachusetts Institute of Technology (MIT), and from Chicago (co-)author a disproportionate share of articles in their respective home journal.... We study this question in a difference-in-differences framework, using data on both current and past author affiliations and cumulative citation counts for articles published between 1995 and 2015 in the QJE, JPE, and American Economic Review (AER), which serves as a benchmark. We find that median article quality is lower in the QJE if authors have ties to Harvard and/or MIT than if authors are from other top-10 universities, but higher in the JPE if authors have ties to Chicago. We also find that home ties matter for the odds of journals to publish highly influential and low impact papers. Again, the JPE appears to benefit, if anything, from its home ties, while the QJE does not. 

On the bottom end as well, 

articles with a Chicago aliation in the JPE are less likely to be amongst the group of relatively low impact articles (i.e., to rank among the 25% or 10% of least cited articles published in the three journals in a year) than articles in the JPE authored by researchers from other top-10 institutions. 

Those are the what, but not the why. These findings naturally provoke some thought from my time at Chicago, and as JPE editor. 

Thursday, March 2, 2023

Lessons from Sargent and Leeper

At the AEI fiscal theory event last Tuesday Tom Sargent and Eric Leeper made some key points about the current situation, with reference to lessons of history. 

Tom's comments updated his excellent paper with George Hall "Three World Wars" (at pnas,  summary essay in the Hoover Conference volume). Tom and George liken covid to a war: a large emergency requiring immense expenditure. We can quibble about "require" but not the expenditure. 


(2008 was a little war in this sense as well.) Since outlays are well ahead of receipts, these huge temporary expenditures are financed by issuing debt and printing money, as optimal tax theory says they should be. 

In all three cases, you see a ratcheting up of outlays after the war. That's happening now, and in 2008, just as in WWI and WWII. 

After WWI and WWII, there is a period of primary surpluses -- tax receipts greater than spending -- which helps to pay back the debt. This time is notable for the absence of that effect. 


We see that most clearly by plotting the primary deficits directly. The data update since Tom and George's original paper (dots) makes that clear. To a fiscal theorist, this is a worrisome difference. We are not following historical tradition of regular, full employment, peacetime surpluses. 


The two world wars were also financed by a considerable inflation. The important consequence of inflation is that it inflates away government debt. Essentially, we pay for part of the war by a default on debt, engineered via inflation. 

Tuesday, February 28, 2023

FTPL Videos

 Two great videos just dropped related to fiscal theory. 


The first is an "Uncommon Knowledge" interview with Peter Robinson. We start with fiscal theory and move on far and wide. Peter is a great interviewer, and the Uncommon Knowledge production team put together a great video of it. Pick your link: Video at Hoover (best, in my view); Hoover event page with podcast, links and more info, Youtube, Twitter, Facebook


Second, Michael Strain at AEI moderated a great panel discussion on fiscal theory with me, Robert Barro, Tom Sargent and Eric Leeper. Three of the founding fathers of fiscal theory offer thoughtful comments, and Michael had provocative questions. I start with a 20 minute presentation, with slides, so this is the most compact "what is the fiscal theory" video to date. It's at the AEI event page or Youtube 

Wednesday, January 4, 2023

Fun Fisherian Graph

In working on a revision to fiscal theory of the price level chapter 5 on sticky price models, and a revision of "Expectations and the neutrality of interest rates" I came up with this fun impulse-response function. It  has an important lesson about interpreting impulse response functions.


It's a response to the indicated interest rate path, with no change in fiscal policy, in a simple new-Keynesian model with short-term debt. 

Rational expectations new-Keynesian models have the implication that higher interest rates raise inflation in the long run. They also tend to raise inflation in the short run. I've been looking for better mechanisms by which higher interest rates might lower inflation in the short run in these models, without adding a contemporaneous fiscal austerity as standard new-Keynesian models do. Fiscal theory explores a model based on long-term debt that does the trick, but has a lot of shortcomings. So I'm looking for something better. 

This graph has only short term debt. I generate the pretty interest rate response by hand. It follows \(i_t=30e^{-1.2t}-29.5e^{-1.3t}-0.05.\) Then I compute inflation and output in response to that interest rate path. 

Wow! Higher interest rates lead to high real interest rates,  send inflation down, and create a little recession. Once inflation is really lowered, the central bank can lower interest rates. The price level (not shown) falls nearly linearly, as we often see in VARs.   

Doesn't this look a lot like the standard story for the 1980s? A big dose of high real rates lowers inflation, and then the Fed can follow inflation downward and get back to normal at a lower rate. 

That analysis is totally wrong!  In this model, a higher interest rate always leads to higher inflation in both the short and the long run.  Inflation is a two-sided moving average of interest rates with positive coefficients. Inflation declines here in advance of the protracted interest rate decline starting in year 2. Lower future interest rates drag inflation down, despite, not because of the rise in interest rate from year 0 to year 2, and despite, not because of the high real interest rates of that period. Those high real rates add interest costs on the debt and are an inflationary force here.  If the central bank wants a disinflation in this model, it will achieve that sooner by simply lowering interest rates immediately. The Fisherian effect will kick in faster, and it will not be fighting the fiscal consequences of higher interest costs on the debt. 

Beware facile interpretations of impulse-response functions! It would be easy to read this one as saying high interest rates bring down inflation and cause a recession, and then the central bank can normalize. But that intuition is exactly wrong of the model that produces this graph.  

The model is \[ \begin{align*} E_t dx_{t} & =\sigma(i_{t}-\pi_{t})dt\\ E_t d\pi_{t} & =\left( \rho\pi_{t}-\kappa x_{t}\right) dt \\ dv_{t} & =( rv_{t}+i_t-\pi_{t}-\tilde{s}_{t}) dt  \end{align*}\] Parameters are \(\kappa = 0.1, \  \sigma = 0.25,\   \rho = 0.1,\ r = 0.01.\) I used a lot of price stickiness and an unrealistically high \(\rho\) to make the graph prettier.  

Update: For Old Eagle Eye. I'm plotting an impulse response function. Variables start at zero, there is one shock, then we solve the deterministic version of the model. The system has two variables with expectations, and two unstable eigenvalues. So we solve forward to determine the initial conditions uniquely. All explained in FTPL, see especially the new Chapter 5 and pointer to the Online Appendix with formulas.