Sunday, November 15, 2015

Hysteresis and Monetary Policy

In the Washington Post last week, Larry Summers wrote about some new research finding evidence of "hysteresis."  This is a term borrowed from the natural sciences for when temporary occurrences have lasting effects - e.g., when you hold a magnet up to a piece of metal, the metal remains magnetized even after you remove the magnet.  In macroeconomics, hysteresis occurs when an economic downturn has a lasting effect on economic capacity (i.e., reduced "potential output"); that is, lack of demand creates its own lack of supply.

Hysteresis could occur through a number of channels. Consider an economy described by an aggregate production function Y* = AF(K,N*) where potential GDP (Y*) depends on productivity (A),  capital (K) and labor at its "natural" or "full-employment" level, N*.  A recession occurs when output falls below Y* and labor is below N* (i.e., there is unemployment in excess of the "natural rate").  Hysteresis implies that there is a lasting impact on Y* - this could occur through technology, capital or labor.

All three channels could be operative. In the past several years, productivity growth has been sluggish, though its not clear if this is linked with the recession (productivity trends are always somewhat mysterious).  The recovery of investment (the rate of flow into the stock of capital) from the recession has been less than spectacular, even taking out housing - the share of GDP devoted to nonresidential fixed investment is somewhat below its peak in previous expansions. 

Here, I want to focus on labor, where the hysteresis effects are pretty evident, and raise an interesting policy dilemma. 

Although the unemployment rate has fallen to what we might consider a reasonably healthy level of 5% (the normal turnover of a healthy labor market generates some unemployment so we never expect it to get to zero), the labor market still clearly bears the scars of the 2008-09 recession.

The duration of unemployment spells rose to unprecedented levels and has remained elevated (a useful comparison is to the 1981-82 recession - the unemployment rate peaked at 10.8% at the end of 1982, but the dynamics of duration were not nearly as severe).
People with spells of long-term unemployment have a harder time finding jobs.  But looking at the unemployed leaves out those who left the labor force entirely.  The last several years have seen a significant drop in labor force participation rates, even among people aged 25-54 (focusing on this group is a rough way to control for the drop in overall participation due to an aging population, though as this Calculated Risk post notes, there is a composition effect even within the 'prime age' group).
The labor market clearly is not as robust as the headline unemployment rate suggests.

What are the implications for monetary policy of having a high proportion of long-term unemployed, and possibly a substantial latent group of unemployed who have left the labor force?  One answer is suggested by this St Louis Fed blog post by Stephen Williamson:
[I]f we think of the long-term unemployed as being subject to the mismatch problem and highly likely to leave the labor force, then these unemployed workers are not contributing much to labor market slack. They are unlikely to be hired under any conditions. 
That is, the unemployment (and presumably the depressed particpation rate, too) is "structural" in nature, and not amenable to any improvement in aggregate demand that might be generated with expansionary monetary policy.

An alternative view is that the long-term unemployed, and some of those who have exited the labor force, could be brought back into employment by particularly strong aggregate demand - what used to be called a "high pressure" economy.  This would be possible if the forces of hysteresis work in both directions, as this 1999 paper by Laurence Ball suggested.

That seemed to me to be what Janet Yellen was hinting at in her September speech at UMass-Amherst when she said:
Reducing slack along these other dimensions may involve a temporary decline in the unemployment rate somewhat below the level that is estimated to be consistent, in the longer run, with inflation stabilizing at 2 percent. For example, attracting discouraged workers back into the labor force may require a period of especially plentiful employment opportunities and strong hiring. Similarly, firms may be unwilling to restructure their operations to use more full-time workers until they encounter greater difficulty filling part-time positions. Beyond these considerations, a modest decline in the unemployment rate below its long-run level for a time would, by increasing resource utilization, also have the benefit of speeding the return to 2 percent inflation. Finally, albeit more speculatively, such an environment might help reverse some of the significant supply-side damage that appears to have occurred in recent years, thereby improving Americans' standard of living.
It seems to be that doing this would likely entail the Fed overshooting its 2% inflation target.  I have my doubts about their willingness to do this (and Yellen certainly did not suggest it).  And for it to work, inflation expectations would need to remain anchored (i.e., if any additional inflation just ratched up expectations, it would not bring unemployment down).

Sunday, September 20, 2015

One of These Things is Not Like the Others

Among the steps the Fed has taken to increase transparency in recent years is the release of projections by the board members and regional bank presidents.  This includes the "dot plot" indicating each participant's belief about what the appropriate federal funds rate target will be at the end of this year and the next three years.

One of the dots from the latest release (I've indicated with a red arrow) shows a preference for a negative fed funds rate this year and next, and a much lower rate than everyone else expects at the end of 2017.
People on twitter seem to think its most likely Minneapolis Fed President Kocherlakota's dot.  It called to mind this, from the deep recesses of childhood memory:
(That's from Sesame Street). 

Of more serious interest, the projections also included a reduction in the median "longer run" federal funds target, to 3.5%, from 3.8% at the last release in June, and also a lower estimate of the "longer run" unemployment rate, which might be taken as a proxy for a NAIRU estimate (see Krugman).

Friday, September 11, 2015

Rodrik on Economic Models

There is an an excellent piece by Dani Rodrik on economic methodology at Project Syndicate:
Economics is not the kind of science in which there could ever be one true model that works best in all contexts. The point is not “to reach a consensus about which model is right,” as Romer puts it, but to figure out which model applies best in a given setting. And doing that will always remain a craft, not a science, especially when the choice has to be made in real time.

The social world differs from the physical world because it is man-made and hence almost infinitely malleable. So, unlike the natural sciences, economics advances scientifically not by replacing old models with better ones, but by expanding its library of models, with each shedding light on a different social contingency.
Or, as Keynes put it, "Economics is the science of thinking in terms of models joined to the art of choosing models which are relevant to the contemporary world." 

Rodrik goes on to discuss Borges' story "On Exactitude in Science" - a parable about cartographers who make a map on the same scale as the world it was meant to represent.  This story, which was our reading for Econ 110 yesterday, illustrates the point that "more realistic" isn't necessarily better.

Thursday, September 10, 2015

A Note on "Credibility"

Fed watchers are speculating that the FOMC meeting later this month might be the occasion to raise the federal funds rate target off the "zero lower bound," where it has been since December 2008.  In a column arguing against such a move, Larry Summers writes:
From the Depression to the Vietnam War to the Iraq war to the euro crisis, we surely should learn that policymakers who elevate credibility over responding to clear realities make grave errors. The best way the Fed can maintain and enhance its credibility is to support a fully employed American economy achieving its inflation target with stable financial conditions. The greatest damage it could do to its credibility would be to embrace central-banking shibboleth disconnected from current economic reality.
At the Fiscal Times, Mark Thoma writes:
The inflation problems of the 1970s, the loss of Fed credibility that came with it, and the need to impose the Volcker recession in the early 1980s to bring inflation down to tolerable levels made an indelible impression on policymakers who lived through that time period. The Fed’s trigger-happy response to any suggestion of an inflation problem is directly related to the desire to never let such an inflation outburst happen again.

But it has been more than four decades since the beginning of the inflation problems of the 1970s, and the economic environment in which monetary policy operates has changed considerably since that time. Those changes support patience, particularly in response to increases in wages, wages that have been stagnant since the 1970s even as labor productivity has been increasing.
The "credibility" argument in monetary policy is based on the idea that the central bank will be tempted to use inflation to "overheat" the economy and bring unemployment down below its "natural" (or equilibrium) levels for political reasons - e.g., to help the incumbent party in an election year.  Any gains would be, at best, short-lived, as people would incorporate a higher level of inflation into their expectations and set wages and prices accordingly.  Based on this logic - which seems helpful for interpreting how we got into the "stagflation" of the 1970s - economists look for policies and institutional structures to correct this perceived inflationary bias.

In the past several years, this logic seems turned on its head.  If anything, the biases of our monetary policymakers appear to be in the other direction.  Inflation continues to be subdued, as this plot of one of the Fed's preferred measures, the "core" deflator for personal consumption expenditures, shows:
The red line is drawn at 2%.  Measures of expected inflation are also below 2%.  David Beckworth recently argued that the Fed is acting as if 2% is a ceiling, not a target - he suggests the Fed's behavior is consistent with it aiming to keep inflation between 1% and 2%.

But the the Fed declared in 2012: "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." If the goal is to "anchor" expectations at 2%, the Fed is at risk of failing, but the greater threat to its credibility seems to be too little inflation, not too much.

Saturday, September 5, 2015

China and the Solow Model

Last month, just before China let its currency deprecate and its stock market crashed, the San Francisco Fed published a nice Economic Letter by Zheng Liu, "Is China's Growth Miracle Over?"

China's rapid, but decelerating, growth is broadly consistent with the implications of the classic Solow growth model we teach our intermediate macroeconomics students.  This model predicts that low-income countries should grow quickly, but growth will slow down as they approach the leading countries, whose per-capita growth is constrained by the rate of technological progress. That is, there should be "convergence" in per capita GDP.

As this chart from the letter shows, China is following a similar path to Korea and Japan.
The basic intuition from the model comes from the idea of diminishing marginal product of capital - i.e., where capital (machinery and equipment) is scarce, the increase in output from adding an additional unit is greater than where it is already abundant.  This diagram of output per capita (y) as a function of capital per capita (k) illustrates,
where the slope is the marginal product of capital (MPk).

The idea can be extended to include "human capital" (i.e., knowledge and skills), as Mankiw, Romer and Weil did in a 1992 paper.

While the Solow model gets the broad contours of the growth experiences of Korea, Japan and (it seems so far) China correct (and does pretty well for the US as well), it does miss a couple of big things:

(1) A diminishing marginal product of capital implies that the financial rewards to investing in a low income country should be vastly higher than in high-income countries.  In a world where people can invest across borders, this implies a huge incentives for financial flows from high-income to low-income countries, but we do not observe such large net flows.  This was the puzzle Robert Lucas noted in a 1990 paper.

(2) While the experiences of some low-income countries is consistent with the convergence hypothesis; in many cases, low-income countries have fallen further behind (or, as Lant Pritchett wrote, "Divergence, Big Time.").  From the standpoint of the Solow model, growth "miracles" like those of Korea are to be expected, and the real puzzle is the fact the failure of so many countries to converge.

As Moses Abramovitz pointed out in 1986, it is usually a subset of the low-income countries that are growing fastest.  This would suggest there are forces for convergence, but something is preventing them from applying everywhere.  Current thinking is that the answer lies in "institutions" - the set of legal rights, culture, and governance which shape the economic environment and incentives for people to take actions within it, including to accumulate capital.

This is where assuming that China will continue to follow in the convergence footsteps of Korea and Japan may be questionable.  While China's institutions have gotten it this far, there are reasons to doubt whether they are appropriate for achieving levels of GDP per capita comparable to Korea, Japan and Europe, as this column by Brad DeLong and this by Eduardo Porter discuss.  That said, the institutions in the US during its late 19th century industrialization were hardly what an economist would recommend (in particular, corruption was rampant), and yet it somehow managed to take over leadership in per capita GDP from Britain.

Friday, August 28, 2015

Economics is More Than You Think

and it helps you learn how to think....

One of the challenges in teaching economics is that many come to it with incorrect expectations - people seem to view it as akin to accounting or finance.  In a liberal arts setting, the students (and their parents) may believe it is the closest thing they can get to a business major (this paper provides evidence on this point).
This short video from the American Economic Association - "A Career in Economics - It's Much More Than You Think" - does a nice job of correcting some of these misconceptions.

However, I think the video misses one of the main reasons for studying economics: the habits of mind - "critical thinking skills" - it helps students develop (I wrote more about this here).  Most of our students aren't going on to careers in economics, and they will forget many of the specifics, but being able to think coherently about tradeoffs and the linkages between assumptions and conclusions is a lifelong benefit.

So, yes, people who are interested in business should study economics, as should people who are interested in a career in economics (my own advice about that is here), but so should everyone else!

Wednesday, August 19, 2015

Opportunistic Flexibility

Last week, China moved to allow more flexibility in its exchange rate.  In this case, that meant a downward movement - headlines about a "devaluation" were rather overstated, though, as the depreciation from Monday to Thursday was about 3% (followed by a slight rise on Friday).  Last week's change is at the end of the graph:
Note, the graph is the yuan price of a dollar, so a downward movement is a yuan appreciation.

China has been criticized over the years for keeping its exchange rate undervalued to support its exports.  The graph shows that it has allowed the yuan to rise quite a bit since 2005, though it has done so in a controlled manner and took a pause for about two years starting in mid-2008.  Its appreciation has helped China make progress on one aspect of "rebalancing" - reducing its dependence on exports.  China's current account surplus is considerably smaller relative to GDP than it was in 2006-08:
So, does this move represent a return to China's old ways of undervaluing its currency to gain a competitive edge for its exports?

Well, yes and no...

As it has followed the dollar, and the dollar has risen, the yuan has appreciated in real terms.  This chart shows a trade-weighted average of the dollar:
During the last year the dollar has appreciated significantly and the yuan has been along for the ride.  Currency appreciation - which makes Chinese goods relatively more expensive on world markets - combined with a slowing economy led to political pressure for a change of course.  The Times' Keith Bradsher writes:
In a little-noted advisory to government agencies, the cabinet said it was essential to fix the export problem, and the currency had to be part of the solution.

With the government keeping a tight grip on the value of the renminbi, Chinese goods were more expensive than rivals’ products overseas. The currencies of other emerging markets had fallen, and China’s exporters could not easily compete.

Soon after, the Communist Party leaders issued a statement also urging action on exports.
However, China has also been moving in the direction of greater financial openness; this entails allowing freer exchange rate movements (as I discussed in this previous post), particularly if it wants the yuan to become an international reserve currency (a status Krugman rightly notes is highly overrated).  At Project Syndicate, Yu Yongding writes:
From now on, China’s government declared, the renminbi’s central parity rate will align more closely with the previous day’s closing spot rates. This suggests that the devaluation was aimed primarily at giving the markets a greater role in determining the renminbi exchange rate, with the goal of enabling deeper currency reform.
So, yes, China has other reasons for moving to a more flexible exchange rate, but it is convenient for them to take a step in that direction at a moment when doing so means a fall in the yuan that will boost demand for Chinese goods.

Tuesday, August 18, 2015

Stories from the Macro Wars

Ian Parker's recent New Yorker profile of Yanis Varoufakis included this nugget: "He has written of his hope, as a professor, to present economics as 'a contested terrain on which armies of ideas clash mercilessly.'"

That may be an apt description of macroeconomics in the 1970s and 1980s.  On his website, Paul Romer has offered an interesting take on the methodenstreit between the dynamic general equilibrium approach (so-called "freshwater" macro, championed by Robert Lucas) and Keynesian macro-econometric models (the "saltwater" camp).  Romer is particularly critical of Robert Solow, arguing that his dismissive attitude towards Lucas et al., contributed into a counterproductive hardening of differences. He writes:
Solow also seemed to be motivated to attack harshly because he was concerned that the type of model Lucas was developing might undermine political support for active countercyclical policy. To his credit, there was a legitimate basis for this concern. The new Chicago school of macro eventually did oppose an active response to the financial crisis and its aftermath. But the type of response that Solow exemplified may actually have contributed to the emergence of this new Chicago school. In retrospect, if the goal was to maintain support for active macro policy, the better course would have been to take seriously what the rebel group that was forming around Lucas was saying. This might have kept the rebels from cutting off contact with all outsiders, even those who were taking seriously the issues they were raising.
Brad DeLong and Paul Krugman responded in defense of Solow. DeLong writes:
And, at this point, Romer ought to say that Solow’s and Hahn’s criticisms were (a) no more biting in their rhetoric than the criticisms that Stigler, Friedman, and company had been inflicting on their victims at Chicago for a generation, and (b) correct and accurate.
Romer has more interesting detail in his response, including this summary of the main points:
In the summer of 1978, Lucas and Sargent were making three claims:
(a) Existing multi-equation macro simulation models were not identified. That is, these models summarized correlations in the data but did not yield reliable statements of the form “if the government does X, this will cause Y to happen.”
(b) It was time to use SAGE models to address such fundamental questions about economic fluctuations as why changes in the supply of money influence economic activity; and
(c) SAGE models will imply that an active monetary policy cannot stabilize economic fluctuations.
Solow thought that Lucas and Sargent were wrong about the policy ineffectiveness claim (c). DeLong, Krugman, and I all agree. In the 2013 introduction to his collected papers, Lucas uses some asides about the Great Depression and the Great Recession to admit that now even he agrees. Claim (c) is what DeLong and Krugman have in mind when they say that  Solow was right and Lucas was wrong.
Yet all macroeconomists now agree that Lucas and Sargent were correct about the fatal problems with the large simulation models. Much of Solow’s response amounted to an implausible denial that there was anything wrong with them. So on this point, the roles are reversed. Lucas and Sargent were right and Solow was wrong.
[Romer uses "SAGE" to refer to general equilibrium models].  See also: this from Krugman, and this from DeLongDavid Glasner has a thoughtful post putting things in a broader context.

In his post, Romer cites several papers, including Lucas and Sargent's "After Keynesian Macroeconomics," from the 1978 Boston Fed conference.  Perhaps it should be known as "the throwdown in Edgartown."

Fascinating stuff... but fortunately for contemporary macroeconomists - particularly those of us with conflict-averse midwestern temperaments - things aren't nearly so rancorous now.  There certainly are differences of inclination and opinion, and economists can be blunt in expressing their differences, but the "saltwater" vs. "freshwater" cleavage is largely a thing of the past, as this Steven Williamson post explains.  Since the wars of the 1970s and 80s, there has been some convergence: macroeconomists have developed a class of models - sometimes called "New Keynesian" - which respond to Lucas' methodological critique but also allow for a stabilizing role for macroeconomic policy.  That's not to suggest we've figured it all out, of course; this recent Mark Thoma column highlights some of the weak points of contemporary theory.

Thursday, August 6, 2015

NPR Visits Keynes' (Sister's) Grandchildren

One of the pleasures of teaching is the opportunity to re-read the articles I assign to my students; one particular favorite that I look forward to each semester is Keynes' essay "Economic Possibilities for Our Grandchildren."  NPR's Planet Money recently did an episode about it, focusing on Keynes' famously incorrect (thus far) prediction of a 15-hour workweek.  Although Keynes had no progeny, they did check in with his sister's grandchildren, as well as Harvard economist Richard Freeman - all of whom seem to be hard workers. I discussed some ideas about why we're not enjoying so much leisure in a post last year.  Tim Harford also has some thoughts on his blog.

The prediction about leisure was part of Keynes' more general forecast that economic growth would solve the "economic problem" of scarcity (and his guess about the rate of growth was pretty accurate), and speculation about the social change that would result.  In a similar spirit, in his Bloomberg column, Noah Smith suggested that a post-scarcity world might be like Star Trek: The Next Generation.  He concludes:
In other words, the rise of new technology means that all the economic questions will change. Instead of a world defined by scarcity, we will live in a world defined by self-expression. We will be able to decide the kind of people that we want to be, and the kind of lives we want to live, instead of having the world decide for us. The Star Trek utopia will free us from the fetters of the dismal science.
Or, as Keynes put it in 1930:
Thus for the first time since his creation man will be faced with his real, his permanent problem- how to use his freedom from pressing economic cares, how to occupy the leisure, which science and compound interest will have won for him, to live wisely and agreeably and well.

Thursday, July 30, 2015

Pushing on a String

One for the footnotes: Timothy Taylor has tracked down the origin of the "pushing on a string" metaphor for expansionary monetary policy in a depressed economy.  It looks like we owe it to Maryland congressman Thomas Alan Goldsborough, who used it in a 1935 hearing with Fed Chairman Marriner Eccles.