As Brad DeLong says, sigh. Greg Mankiw challenges the administration's prediction of relatively fast growth a few years from now on the basis that real GDP may have a unit root — that is, there's no tendency for bad years to be offset by good years later.
I always thought the unit root thing involved a bit of deliberate obtuseness — it involved pretending that you didn't know the difference between, say, low GDP growth due to a productivity slowdown like the one that happened from 1973 to 1995, on one side, and low GDP growth due to a severe recession. For one thing is very clear: variables that measure the use of resources, like unemployment or capacity utilization, do NOT have unit roots: when unemployment is high, it tends to fall. And together with Okun's law, this says that yes, it is right to expect high growth in future if the economy is depressed now.
But to invoke the unit root thing to disparage growth forecasts now involves more than a bit of deliberate obtuseness. How can you fail to acknowledge that there's huge slack capacity in the economy right now? And yes, we can expect fast growth if and when that capacity comes back into use.
Narayana Kocherlakota would argue that not unit roots but rather money is the root of all evil. Or do I have that backwards?
The problem is that the support for this growth is very cheap energy. Cheap oil is history. Those who see infinite growth as sustainable are delusional. You are much smarter than I am but even "slack capacity" won't help this situation. We are headed for a total transformation in the way we live our daily lives.
Even if you don't believe the theory, here's the reality. I was talking to the president of a window manufacturing company. They laid off every worker they could to stay afloat. Now, there's been a slight uptick in their orders. He has no way of ramping up production without bringing people back. So, even the slightest bit of additional demand is going to cause a higher amount of employment than if the economy wasn't depressed.
I imagine there are a lot of other industries in this same situation or close to it.
Yes, real GDP has a unit root, but the rate of growth does not, meaning that whatever rate of growth we had, in the past we have still recovered towards that average. If history is any guide, we will recover.
And, well, unemployment, too, does have a unit root (at least on postwar data), that is we have seen periods of persistent unemployment. There is no tendency for unemployment to magically disappear (same with capacity utilization, which is jus the same as unemployment, just inverted –plot it).
A unit root does not imply that GNP is a random walk (Mankiw knows this perfectly well). An ima with ma coefficients adding up to less than one in absolute value has a unit root. A random walk times a mean reverting series has a unit root, a random walk plus a mean reverting series has a unit root.
The question of whether negative growth is followed by unuually high growth absolutely can not be answered by testing for a unit root.
Also the evidence for a unit root in GNP is largely based on the depression. Huh ? that's the strongest example of mean reversion. Yes but if you estimate an ar(1) you are surprised that the economy managed to decline so much for 3 years running . The test has no power against an arma with heteroskedastic disturbances (one called "the Hoover years"). Everyone knows this and no one (who I know of) has talked about unit roots for about a decade.
Mankiw is indeed being deliberately obtuse.
Out of curiosity, why do you define 73-95 as slow growth? These years look no different on a chart of GDP growth as a percentage than the other years other than they have are relatively stable years without wild fluctuations. If anything, I would group '83-'99 together. In those years, there was only one garden variety recession with regular growth rates.
Wonkish – My point is if I were to integrate percentage growth over that time period, I would bet that the growth would be similar to other periods while also being more uniform and less taxing to the average worker.
I mean this as a serious question from a layman.
While there is slack capacity, that is no guarantee that it is the right capacity. Just because we have 12 auto plants idle doesn't mean people will want that many new auto mobiles in the coming years (especially if we have used cap and trade to make gasoline more expensive.) Structural shifts in demand could take a prolonged period of building new productive capacity (such as solar panel plants, lithium battery plants and smart grid infrastructure.) Now demand may rebound into the old pattern of consumption, but there are scenarios where it will not.
What if the capacity was built up to service unsustainable consumer demand, which perhaps would never return to its glory days? And what if the idle capacity can get obsolete?
At some point the growth is indeed going to reverse but to expect, especially in today's context, a fast reversal a year from now is certainly not as obvious as presented here.
Yes Dr. Krugman, but both you and Mankiw ignore the real world facts that in the future there will be higher taxes, and huge budget deficits to finance which will raise interest rates. Both of these facts, as opposed to theoretical debates (root-schmoot who really cares?) will depress our economic growth in the future making the probability of fast growth in the future less likely, even with the excess capacity waiting on the sidelines.
How then, does one explain Japan using this framework?
After all, they have been awaiting rapid growth for well over a decade?
That capacity will only survive to be used if it considered *profitable*, and will rot and fall into disuse if it never finds a level of profits that will enable transition back to an immediate use.
The shipyards of Philadelphia are a great example- at the peak in 1917- they lined the Delaware, and today they are all gone. That capital has fled.
Some of the houses of the boom areas are going to rot and fall into ruin.
First, as I see it, we have no alternative to the stimulus and the Geithner financial plans. They have the least damaging unintended consequences.
But as to the recovery, and Republican disingenuousness notwithstanding, I don't see a zooming recovery either. Not unless we accelerate some kind of domestic manufacturing and business development model.
When we came out of the Great Depression, we were gearing up for manufacturing of all kinds of consumer durables that would turn the postwar period into the longest stretch of economic growth until Clinton.
I don't see how a nation that has no manufacturing can make a dynamic recovery. At the very least we should have a market tax. A "pay-to-play" tax–if you want to take materials abroad, make products and bring them back into the country, into the most lucrative market in the world.
A modest entry tax on all these products across the board would raise about $145 billion which could be used to develop new industries and jobs that could not be outsourced.
If we accelerated the retrofitting of American vehicles, expanded hybrid and plug-in manufacture and alternatives to corn-based ethanol and "clean coal" techniques, we would have a start on reinventing our industrial base.
Otherwise, it is going to be a long, long recovery. The financial sector does not employ large numbers of the kinds of people who grab their lunch buckets and wash up before driving home.
Housing prices will hold and or rise in plenty of desireable places and that value will remain providing the interest rate stays low. The interest rate was a big part of creating the problem we are in. It seems it will remain low for a while longer, which may be why Summers is so opptomistic.
Housing prices are relative to inventory, providing the inventory is similar. The more mediocure the house, the better chance its price will drop. The more desireable the location, the better chance those prices will hold and or rise.
Keep in mind that those caught in todays finacial issue is very much an age oriented issue. Many of those that have been hurt, do not have enough time to recover their retirement assets, but are well positioned with equity in their homes. There will be a significant shift, once this group of boomers takes a breath and sells their equity to regroup (possibly become mobile) There is opportunity for those that have an inventory of small homes in desireable locations. This housing boom will be starting soon, and will be over in about 36 months. Time to get ready. The numbers are substantial.
I am a total lay-person in these matters, but this post is effectively taking on something that David Brooks wrote in his column today, right? Brooks feels that Obama's budget is much too optimistic in it's prediction of economic growth over the next two years, but you and Mankiw feel that it's probable?
As a liberal with a small skeptical streak, I'm predisposed to believe Brooks assertion, but I'd love to know that it's likely to be wrong.
Gotta put those assets to use somehow. When people are ready to buy what that capacity will produce, it will all even out. Even if the new economy requires that capacity to produce something different. The conversion cost to produce that something different may be the very thing standing in the way if our growth it seems.
What happens if we all decide that we can live with less stuff, i.e. demand falls just because a fair number of us aren't interested anymore? Is there a sustainable economic model that doesn't involve ever increasing consumption?
That fast growth could seemingly be accelerated if Americans' sorely lacking economic education were countered by chalk-board sessions with President Obama and a Nobel Laureate – sessions helping people make economic decisions that get the most macro-bang for their spendable bucks. Since half the U.S. population was born after 1976 they have no frame-of-reference that does not include the tax-cutting, supply-side, "voo-doo" economics which has so spectacularly failed.
The mind-set that exists in many business commentators, who usually give themselves away by saying "Obama" in one sentence, then "President Bush" in the next, cannot be counted on to do such economic education. They have descended into axe-grinding rants, wanting an RTC-type facility that would wipe the slate clean at the banks, and provide low-hanging fruit for hedge funds to pluck. They are blinded to the fact that the S&L crisis had actual hard assets to dispose of – this time Wall Street has created a virtual mountain of paper with synthetic values on which to calculate virtual profits used to extract cold hard cash bonuses. There are very few hard assets to put into an RTC-type facility, which means the solution will be different this time, and will take time to un-wind.
Dollars are indeed on the side-line and will come back in when confidence is restored, which will cause home prices to stop declining. Americans know they have been lied to and fleeced and have seen the hard-won 1990's once-in-a-lifetime budget surplus squandered. Until it is as least as hard to register as a hedge fund manager as it is to get the Nevada Gaming Commission to license a craps dealer in a Vegas casino, investors will know where their money is safest.
The notion that a complicated nonstationary real-world process such as that which generates the GDP can have a unit root is implausible. The notion that it could reliably be known to have a unit root is absurd.
A noted psychologist, Abraham Maslow, wrote, in Toward a Psychology of Being, "capacities clamor to be used." In the model recovery cited most often as support for a variety of arguments, the United States came roaring back from the Great Depression on the strength of manufacturing capacity, as well as ability to ramp up the capacity to wartime levels. Our *man*power capacity was not so great; hence the great opportunity granted to women — Rosie the Riveter. Our materials capacity was not so great; hence the enormous recycling on the household level, of oils and metals. Our industrial capacity was not, as now, capable of both wartime and peacetime production.
After WWII my family did not have any excess capacity, as my father lost his job designing aircraft, and the riveting jobs were also gone, for my mother. That is to say, there was a wrenching shift from wartime economy to civilian economy, aided by women staying home, education of surviving soldiers, and the growth of advertising, producing a fairly stable decade in the fifties.
The contribution of the Great Depression programs were primarily in maintaining workforce capability — the ability of men to work at government projects, maintain self-esteem, and nourish the habit of work. Women — more than recognized, I believe — also worked, at far smaller hourly wages than men, creating the capacity for women to become defense industry workers (riveters and others) during WWII.
My argument, then, is first that there was less excess capacity at the onset of WWII than we might think, so that excess capacity now will not "clamor to be used" in a WWII-like recovery.
Second, I would argue that the mechanism of adjusting the capacity of the workforce by the call to women to join the workforce in WWII, and the equally strong call for women to return to the home, following the war, is somewhat less likely to be successful today. At least I hope so.
How does an excess-capacity model apply to global and U.S. recovery today? I am reminded of a model of the way the housing bubble crippled development of other kinds of industry, and an analogous view that there is a "government-bailout bubble" propping up bad companies and crippling more stable companies in the process.
It seems to me that excess capacity — e.g., a glut of already built houses — does not bring us out of depr/ecession. To do so, we need innovative uses for the capacity we have, and the ability to ramp up vocational and post-secondary education to meet the demand for retraining for new jobs — to make potential capacity actual. Otherwise, economics remains a dismal science.
In the end, Maslow's theory indicated that capacities that clamor to be use follow a developmental path that came to be called self-actualization — and then got popularized and bastardized and what all.
An outline, Dr. Krugman, of what the world (or United-States) developmental path toward the actualization of the capacity would be helpful.
Ask Greg to give you some odds. Good forecasts are 50/50 and so if you believe the forecast is good, then there should be no reason for you to make the wager. If he will give you 2 to 1, you should take it.
Perhaps excess capacity could produce the kind of GDP numbers of which you are speaking, but with so much money going to the government in taxes, and later on interest, how's this capacity to be tapped? Isn't there an offsetting crowing out effect?
The best I can see out of this discussion is to discover who is less wrong; not to intriguing.
The unit root hypothesis is well-known to students of Keynes. We remember it as "The market can stay irrational longer than you can stay solvent. " Krugman, you are right to assume that over the very long term, indicators such as the GDP and employment will undergo mean reversion and return to sane values. However, in the meantime, how long can we go without oxygen? Without food? Without a banking sector? Without an economy? How patient are we willing to be while we wait for the oxygen to return to the room? It might be a while. Be honest. Deleveraging $58 trillion dollars of total US public and private debt might take some time. Perhaps.
If this were a bunch of factories closing down then capacity exists that can be restored. Banks closing down with worthless assets as collateral don't have capacity to revive. Their wealth was not productive capital, it was debt derivatives. Once the collateral is gone, they are pieces of paper with no claim on productive capital. The wealth tied to those enterprises has been destroyed and is irrecoverable.
You can inflate it back so people have paper money to equal their old bank accounts, you tax the rich until there are no more rich people, but you cannot recover the wealth that was lost.
Could Mankiw be confusing a unit -root problem for statistical estimtion in some relatively long-term time data like a 1960-2008 GNP time series with real-world autoregression in GNP during a particular segment of time like this recession? Could he be obfuscating the theoreticasl/substantive issue by throwing a statistical term at it?