Words Found and Argued

Some time ago, I wrote this:

“The low barrier of entry to accessing and interpreting economic data has created unrealistic expectations of its accuracy and relevance.”

I don’t know if that was me writing down my own thoughts or someone else’s, but I agree.

Incidentally, regarding the dust-up caused by the WSJ’s style guide change allowing data to be used as a singular noun, I’d like to note that while I’m okay with the WSJ’s change, I find their explanation to be lacking a simple point: it’s not simply that usage has evolved away from the plural, it’s that data has evolved from being a plural to being a mass noun. Given the fundamental changes brought about by the volume of data (Did you see what I did there? Volume? Mass noun.) we now produce, I’d argue that this is a case where the change in grammar perfectly mirrors the change in the concept it describes.

Houses on Sand

As the crest of the Mississippi’s flooding rolls southward, I notice that a lot of people are linking to the piece The Control of Nature: Atchafalaya, which was published in the New Yorker and adapted from John McPhee’s book, also titled The Control of Nature.  I strongly recommend it; McPhee does a beautiful job of showing how vital a vulnerable piece of hydrological engineering called the Old River Control Structure is to the way people live in southern Louisiana.

Google’s Cycling Directions are Very Much Still in Beta

I’m excited that Google has published cycling directions, but as they are right now, they might get me in trouble if I follow them:

Suggested Bike Route (between the East Wing of the White House and the Treasury Building)

A Quick Note on Interpreting Poll Results

In The New Republic:

“In Virginia, I’ve argued,Democratic candidate Creigh Deeds, who on his record and on the issues had much to recommend him, suffered at least in part from identification with Obama and the national party.

“The disapproval of Obama among Virginia voters, which began to climb in late July, may have affected their enthusiasm about Deeds. In the final edition of the exit polls, 51 percent of Virginia’s voters disapproved of how Obama has done his job, and 94 percent of them voted for McDonnell. More important, perhaps, is that a lack of enthusiasm about Obama and the national party may have affected turnout.”

It’s true– according to the New York Times exit polls, 51% of voters in Virginia disapproved of Obama, and 94% of those people voted for McDonnell.  That group alone gave McDonnell about 48% of the total vote count.  But– McDonnell didn’t squeak by.  He got about 58% of the vote.  That other 10% came from people who support Obama.  The problem for Deeds wasn’t the approximately half of people who disliked a Democratic President and voted Republican in a closely-divided state, it was the fact that of the 49% of people who approved of Obama, 20% voted for McDonnell.  Had the race been a referendum on Obama, Deeds would have fared far better than he actually did.

To be fair, most of the piece focuses on the issue of turnout.  But even there, the case is weak.  The author spends time mulling over the lack of enthusiasm among African Americans in 2009 as opposed to 2005, but this had no bearing on the outcome of the race– even in 2005, African American voters constituted less than 1% of those casting ballots in Virginia.  He argues that high unemployment is suppressing Democratic turnout, but in Virginia, unemployment has only risen to 6.7 percent– not full employment, but not the pressing issue that it is elsewhere in the country (in the past year, unemployment in Michigan has risen by 6.4 percentage points)– and, more importantly, it’s even lower in heavily-Democratic Northern Virginia, where turnout would be more of an issue for Deeds.  While it’s tempting to try to put a more interesting– and more nationally-relevant– spin on the race, it’s much easier to make a credible argument that the lack of turnout for Deeds was a function of the fact that people just didn’t like him.  Creigh Deeds’s problem wasn’t Barack Obama’s unpopularity, the problem was Creigh Deeds’s unpopularity.

So, while the author’s other points about the 2010 elections may very well be true, they’re not proven by this particular race.

Brad DeLong says…

Somewhere in the World There Must Be Someone Who Understands the Unemployment Insurance Seasonal Adjustment Factor

But it sure ain’t me:

Initial Claims for Unemployment

Looking at this time series, the seasonal adjustment does look a little crazy, but I promise– it’s not that bad.  Let’s go to the ten-year:

Initial Unemployment Claims Over Ten Years

So, yes, that spike looks huge, but historically, it’s only really big.  Obviously, it’s possible that the seasonal adjustment should be different in recessions.  We could test for this– we could set up a Markov-switching model with trigonometric terms, and allow switching in those terms to see whether the adjustment should be smaller or larger in recessions.  It’s possible that this wouldn’t be terribly enlightening, as different recessions can be very different, but it wouldn’t take too terribly long, and I’m sure Brad has some graduate students he could put to work.

Oh, Chicago

From Steve Levitt: “The other day I was walking through the halls of the University of Chicago economics department and heard a faculty member say that the right rule of thumb for government spending is that it is worth only 10 cents on the dollar because of inefficiency.”

I’m open to suggestions as to what rules of thumb should be applied to UChicago economics.

Happy Fall!

Two melons were laying in a field when one turned to the other and said, “You know, we’re going to have to invite my family to the wedding.”  The other asked, “Why?”  “Because we cantaloupe!”


Cantaloupe from Bigg Riggs

On Enjoying Your Work

From a friend:

One thing that’s hilarious to me is, I had this job that paid me well.  I saved up.  I bought a nice blender.  Instead of buying a 2-dollar skirt at goodwill, I bought an expensive one at a real store.  It was lovely, but it didn’t fill the void.  I think the cliches about that are pretty true.

Fail-Safe Design

A quick lunch-hour observation…

Quincy Adams at The RBC is absolutely right that the control system for Metro trains, as described in the Washington Post, contains a fundamental design flaw.  I’d argue, however, that an effective solution can be designed that is far simpler than Quincy’s suggestion.  In fact, the system could have been designed far more safely, without requiring technologies that weren’t available when the system was built (such as GPS or most other positive-location technologies).  All that was necessary was that the system be designed according to a fail-safe philosophy.

Quite simply, a fail-safe design requires that the default action of the system be the one that results in least harm.  An example can be found on high-speed trains in Europe– if the operator removes his foot from a sensor on the floor for more than a specified amount of time, an alarm is sounded and he’s given a few seconds to tell the system that he’s still alive by pressing a button.  If he doesn’t, the train stops itself.  In fact, almost all trains already have fail-safe systems in parts of their design, such as their pneumatic brakes, which are forced off by the application of air pressure (which compresses springs that apply constant force towards the brake rotor) and are applied when pressure is removed– so that in the event of a pneumatic failure, the train automatically comes to a stop.

The specific idea underlying both of the previous examples is pretty clear– the safest default action for a train (as opposed to, say, an airplane) is usually “stop immediately”, not “full speed ahead”.  In the case of the Metro train system, sensors should be designed to send a positive signal when a train is not present.  Under such a design, two desirable outcomes occur: a sensor failure cannot result in a collision (it instead results in train stoppages requiring manual operation to bypass), and the failure is immediately brought to system operators’ attention.

While such a system can be inconvenient if sensor failures are common, noisy failures generating inconvenience are almost always superior to silent failures generating death.  Also, of course, if the system wasn’t designed to be fail-safe because such failures are common, then it should never have been put into operation.  There may be something I’m missing, but from what information is available, this seems to be an inexcusable failure in design.

Disclaimer: Like Quincy, I am also not a transit engineer, and am also relying on the information from the Post.

A final note: the above is exactly why I’ve disabled cruise control in my car.  If I were to fall asleep or be otherwise incapacitated behind the wheel, I’d rather my foot lift off the accelerator and the car slow down than have it continue to hurtle along, à la Beck: stock car flaming with the loser in the cruise control.


WMATA currently:

Red Line
Disruption at Fort Totten in both directions. Trains are turning back at Rhode Island Avenue & Silver Spring due to a situation outside of Fort Totten station. Shuttle bus service has been established. Expect delays in both directions.

WMATA between 9-10 PM yesterday (unofficial twitter re-broadcast):

Red Line
Disruption at Fort Totten. Trains are turning back at Brookland-CUA & Silver Spring due to a police situation outside of Fort Totten station…

WMATA between 6-7 PM yesterday (unofficial twitter re-broadcast):

Red Line
Disruption at Fort Totten in both directions. Trains are turning back at Rhode Island Avenue & Silver Spring due to a train experiencing mechanical difficulties…

Washington Post:

At Least 6 Killed in Red Line Crash
One Metro train slammed into the back of another on the Red Line at the height of the evening rush yesterday, killing at least six and injuring 70 others in the deadliest accident in Metrorail’s 33-year-history.
The impact of the crash was so powerful that the trailing train was left atop the first train.
Metro officials expected the death toll to rise to at least nine.

WMATA could do better by having slightly stronger wording available for service bulletins in the event that something occurs that shuts down service on their busiest line during rush hour while they try to rescue their passengers.  They could also wait less than an hour an twenty minutes (I received an e-mail alert from them at 6:20 PM) to send out an alert about something that will clearly have a severe impact on service.

What happened yesterday was a tragedy, and improving the safety of Metro service must be the top priority.  After they tackle that, though, I recommend improving their communication with passengers.  It’s really low-hanging fruit; the marginal cost of communication is near-zero. Don’t make riders wait until they’re already in the system to find out that they should have made other plans.  There’s simply no excuse when it’s immediately clear that an emergency like yesterday’s has occurred.  I’m assuming, of course, that the central command learned quickly about what happened (if they didn’t, then it’s a safety issue).

Economics, Energy, and the Environment.