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Archive for June, 2010

Olivia Goes On Sabbatical

I want to wish Olivia Judson well on her year off and on her book project. Science lovers everywhere will miss her. Enjoy her last column before her certain triumphant return. This resonated with me:

For me, ideas are capricious. They appear at unpredictable (and sometimes inconvenient) moments — when I’m in the bath, falling asleep, jumping rope, talking to friends. They are also like buses — it’s never clear when the next one will come, or how many will arrive at once.

[…]

But having an idea is one thing; developing it is another. Some ideas look great from the bathtub, but turn out to be as flimsy as soap bubbles — they pop when you touch them. Others are so huge they can’t easily be treated in 1,500 words or less, or would take two or three months to prepare. Still others — luckily — are just right. But I don’t usually find out which is which until I begin to investigate them. 

(image from jla.co.ok) 

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"Walking And Chewing Gum"

June 19, 2010 2 comments

Martin Wolf explains to deficit hawks that tightening fiscal policy too early could cause more problems in global markets.

Despite the most aggressive monetary policy ever, private sectors moved into huge surpluses. Monetary policy was “pushing on a string”. The fiscal offsets – overwhelmingly due to built-in fiscal stabilisers, not the discretionary stimulus – helped sustain demand in the crisis. But they were insufficient, even with monetary support, to prevent deep recessions. The argument that stimulus was unnecessary is hard to accept. It is easier to believe it was too small, albeit also ill-targeted.

So how quickly should deficits be eliminated? We must recognise the danger here: cutting public spending will not automatically raise private spending. The attempted reduction in the structural deficit might lead, instead, to a rise in cyclical fiscal deficits, which would be running to stand still, or to a reduction in the private surpluses only because income fell even faster than spending. Either outcome would be grim. Yet neither can be ruled out.

As long as output remains depressed, the fiscal support is most unlikely to be inflationary. Nor will it crowd out the private sector: it is more likely to crowd it in. The big question, then, is whether deficits can be financed. My answer is: yes. Remember that so long as the private sector runs financial surpluses it must buy claims on the public sector, unless the developed world as a whole is about to move into huge external surpluses.

Deficits are a real problem, just not now. It’s clear that we should reassure private investors and financial markets by setting up long-term policies for controlling the deficit that don’t depress demand in the short-term. A VAT would be one obvious revenue side solution. Controlling health care costs is the biggest on the spending side. The good news is that the best way to curb the deficit is to enact policies that promote economic growth now. Fiscal restraint now isn’t one of those policies.

Learning English, Reading Evidence

Despite many nativists’ gut feelings and anecdotes, it appears recent immigrants are actually more likely to speak english than previous waves of foreign-born migrants. 

The x-axis is the number of years that foreign-born adults had lived in the United States. The y-axis is the percentage of that group that spoke English.”

World Cup

This is sad.

On a more positive note: Yay for Mexico in its 2-0 win over France! I have high hopes for the US, but first we need a win against Slovenia. 

Categories: Race, Sports, World Cup

More Stimulus Needed?

I’ve defended the stimulus and criticized some of its design; well I still feel similarly, but as Matthew Yglesias points out (via Mark Thoma) fiscal stimulus on net hasn’t happened. Read his whole short post – but here’s the relevant quote from Thoma:

But it’s important to remember that the proper measure for fiscal stimulus is not spending by the federal government; it is spending by all levels of government. And when you look at the contributions to US GDP growth (Table 1.1.2 at the BEA site), total government spending has been a drag on growth over the past two quarters. The increases at the federal level have not been enough to compensate for the spending cuts at the local and state levels.

It is also important to realize that a $787 billion stimulus package over 3 years seems large, but compared to the size of the US economy as a whole (14.2 trillion in 2009) it is easy to see why it might not have been large enough. According to the IMF, “U.S.’s planned stimulus amounts to 2 percent of output in 2009 and 1.8 percent” in 2010.  Krugman most frequently made this point before the Recovery Act passed and argues it now to push for further stimulus.

Consider the long-run budget implications for the United States of spending $1 trillion on stimulus at a time when the economy is suffering from severe unemployment.


That sounds like a lot of money. But the US Treasury can currently issue long-term inflation-protected securities at an interest rate of 1.75%. So the long-term cost of servicing an extra trillion dollars of borrowing is $17.5 billion, or around 0.13 percent of GDP.

And bear in mind that additional stimulus would lead to at least a somewhat stronger economy, and hence higher revenues. Almost surely, the true budget cost of $1 trillion in stimulus would be less than one-tenth of one percent of GDP – not much cost to pay for generating jobs when they’re badly needed and avoiding disastrous cuts in government services.

Also, Bruce Bartlett links to a study which “found that fiscal contraction in the states offset almost 100% of the fiscal stimulus at the federal level in 2009.”

Federal fiscal expenditure stimulus has mostly compensated for the negative state and local stimulus associated with the collapsing tax revenue and the limited borrowing capacity of the states. While this is a significant accomplishment, the net effect is that the consolidated fiscal expenditure stimulus is small, at a time when the private sector’s deleveraging has reduced private consumption. Thus, the fiscal expenditure stimulus did not manage to provide a viable cushion for the negative stimulus associated with private sector’s declining demand.

Summers-Time Class: Gender Studies

June 16, 2010 2 comments

Discussing potential differences in innate abilities between groups remains a controversial topic and research area. Famously, Larry Summers found himself at the center of a nationwide controversy after he upset many of the students and faculty at Harvard when he speculated on the reasons why women might be less represented in math and science fields. John Tierney in The New York Times has written two columns (here and here) that present some research along with his opinions which seem to vindicate Summers. 

The Duke researchers report in Intelligence, “Our data clearly show that there are sex differences in cognitive abilities in the extreme right tail, with some favoring males and some favoring females.”

The researchers say it’s impossible to predict how long these math and science gender gaps will last. But given the gaps’ stability for two decades, the researchers conclude, “Thus, sex differences in abilities in the extreme right tail should not be dismissed as no longer part of the explanation for the dearth of women in math-intensive fields of science.”

Other studies have shown that these differences in extreme test scores correlate with later achievements in science and academia. Even when you consider only members of an elite group like the top percentile of the seventh graders on the SAT math test, someone at the 99.9 level is more likely than someone at the 99.1 level to get a doctorate in science or to win tenure at a top university.

[…]

The gap in science seems due mainly to another difference between the sexes: men are more interested in working with things, while women are more interested in working with people. There’s ample evidence — most recently in an analysis of surveys of more than 500,000 people — that boys and men, on average, are more interested in inanimate objects and “inorganic” subjects like math and physics and engineering, while girls and women are more drawn to life sciences, social sciences and other “organic” careers that involve people and seem to have direct social usefulness.  

You can argue how much of this difference is due to biology and how much to society, but could you really affect it by sending scientists and engineers off to the workshops mandated by the bill now in Congress?  

PZ Myers isn’t too happy with Tierney.

Now here’s the problem: there is no clear marker or metric for success in science. It’s a complicated task, with lots of variables and lots of different strategies for doing well. It’s not like looking for the person who runs the 100 meter dash the fastest, in which we could just line up the applicants, fire a starting gun, and give the job to the first person who crosses the finishing line. So what do we do? We use proxy metrics.

The best proxies are measurements that most closely approximate performance in science. We look at publication records, grants awarded, recommendations of colleagues, the sort of thing we’d expect our new scientist to continue doing. It’s not perfect — maybe the applicant is a neurotic living on the edge who’s about to break down, or maybe they have an abrasive personality that will affect the performance of other faculty — but it’s a good start. It’s what most committees should evaluate most highly in the hiring process. 

[…]

All of those things are still just proxies for the constellation of properties you want in a scientific colleague. We have to balance them to get an idea of the potential of an applicant: it would be insane to hire someone with no experience, no publications, and no grants just because they got straight As in high school and college. But for some reason, in this tedious argument about the suitability of women to do science, all that gets mentioned is a gender difference in performance on standardized tests. 

He then goes on to point out that wealth is also a great predictor of success in test scores. He’s using this example to blow up Tierney’s connection between gender and test scores since obviously wealth isn’t innate. Myers makes some interesting points but this is a poor one. It’s entirely possible (and researchers have made the point before (e.g. Steven Pinker)) that intelligence and wealth are correlated because, unsurprisingly, intelligent people are more likely to be wealthy due to their intelligence helping them get higher paying jobs. In other words, intelligence is a cause of wealth rather than the reverse. 


Real discrimination is a problem, but pretending that no differences exist makes it more difficult to establish when actual discrimination is taking place. At the very least we should be able to discuss the issue without being vilified. If not we might have to sue Mother Nature for age discrimination.


Logically Consistant ≠ Rational

I stumbled on a 2006 paper from Christopher Achen and Larry Bartels of the Center for the Study of Democratic Politics that further confirms my attitude toward voters in general.

Most of the time, the voters are merely reaffirming their partisan and group identities at the polls. They do not reason very much or very often. What they do is rationalize. Every election, they sound as though they were thinking, and they feel as if they were thinking, as do we all. The unwary scholarly devotee of democratic romanticism is thereby easily misled.

This of course shouldn’t be too surprising to people who study how our brains work. Human brains make shortcuts by seeking patterns and putting things in categories. This is a useful and necessary tool so that we can make any sense of a complex and chaotic world. Often it’s hard to break those intuitive theories and stereotypes (and very easy to reinforce them). So as the Achen and Bartels paper helps us see, I’d argue that partisanship and group identity politics is a quick natural substitute, a mental shortcut, for rigorous and rational thinking. Steven Pinker writes in How the Mind Works

[The] mind has to get something out of forming categories, and that something is inference. Obviously we can’t know everything about every object. But we can observe some of its properties, assign it to a category, and from the category predict properties that we have not observed.

When something doesn’t fit our categories we tend to ignore the evidence or alter it to fit our preconceptions instead of the other way around.  Pinker writes,

A third reason we are so-so scientists is that our brains were shaped for fitness, not for truth. Sometimes the truth is adaptive, but sometimes it’s not. Conflicts of interest are inherent to the human condition, and we are apt to want our version of the truth, rather than the truth itself, to prevail. 

Everyone else excited for the 2010 midterms!?


(photo from Wired)

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