Monday, December 11, 2017

Model Decay, Causal Mechanisms and Townhallophobia

[Now with title.]

I know I've been going to the well a bit too often recently in terms of old posts. I'll admit there's an element of laziness here, but I also think it's useful and even important to review old arguments in terms of new developments.

This also gives us a chance to dig a little deeper into pertinent related topics. For instance, despite living in a data obsessed age when every journalists feels the need to pepper reporting with graphs and statistics and models and algorithms (and frequently models mislabeled as algorithms), there are still a number of fundamental analytic concepts that generally evade even the more sophisticated data journalists.

A notable example is model decay. With the exception of the physical sciences, even the best models tend to lose explanatory and predictive power over time (though in the life sciences, the changes can be very slow). This is particularly true in the social sciences where people quickly adapt to conditions, sometimes specifically in response to awareness of the very models in question.

Model decay can happen slowly or suddenly and there's no simple procedure for seeing how well things are standing, but there are red flags you can look out for.

Though I may get some pushback on this, I think most good modelers and researchers at least implicitly have a set of plausible mechanisms in mind when they propose a causal relationship. (If a researcher can't think of any plausible mechanisms that might cause the relationship he or she is seeing, that's probably cause for concern.) For example, let's say a study found that people who purchased a gym membership and did not make serious use of it saw their body fat tend to increase. The researcher might hypothesize that the subjects were rationalizing bad dietary choices based on the belief that they would work off the pounds.

Though these plausible mechanisms are just good guesses, it is a good idea to keep them in mind when considering model decay. If we have reason to believe that the mechanisms for a particular model no longer function in the same way, we also have reason to believe that the model may no longer be viable. Going back to our previous example, imagine that a certain unnamed financial institution buys a health club chain and starts signing up customers without their knowledge. We definitely have reason to believe that the relationship between unused gym memberships and body fat will break down.

With the rise of data-based political reporting, we've also seen an uptick in simplistic A-then-B models. Writers will often explicitly acknowledge that conditions are completely different then turn around and insist that the same relationships that held before hold now.

Consider the incumbency advantage. There's obviously a relationship here, but what are the plausible mechanisms behind it? We could always reach out to political scientists or dig into relevant studies and polling data, but we can also make some pretty good common sense guesses. It's entirely reasonable to suppose that the advantage is at least partially dependent on incumbents being responsive to their constituents' wants and needs and maintaining a strong connection with the people back home through regular contact via multiple channels.

When politicians take stands that are unpopular with their constituents and then abruptly and publicly cut off these channels of communication, there is reason to believe that assumptions about the incumbency advantage may no longer hold.

Here's what we were saying about this ten months ago.

Though, to be perfectly fair, Tennessee has always been a hotbed of leftist radicals

We have all heard the statistics about how difficult it is for a Congressional representative to lose his or her job. This is partially because of things like gerrymandering and spigots of campaign cash, but it also reflects a process that does a pretty good job allowing a reasonably competent and dedicated legislator to keep the constituents fairly happy in his or her district. A big part of that process is the maintaining of good relationships and lines of communication with voters and communities. Many political career has ended when voters felt someone had "lost touch with the people back home."

In this context, stories like the following from Talking Points Memo's Allegra Kirkland take on a special significance.
Constituents requesting that Rep. Jimmy Duncan Jr. (R-TN) hold a town hall on repealing the Affordable Care Act aren't being met with a polite brushoff from staffers anymore. Instead, Duncan's office has started sending out a form letter telling them point-blank that he has no intention to hold any town hall meetings.

“I am not going to hold town hall meetings in this atmosphere, because they would very quickly turn into shouting opportunities for extremists, kooks and radicals,” the letter read, according to a copy obtained by the Maryville Daily Times. “Also, I do not intend to give more publicity to those on the far left who have so much hatred, anger and frustration in them.”

In the first weeks of the 115th Congress, elected officials dropping by their home districts were surprised to find town halls packed to the rafters with concerned constituents. Caught off guard and on camera, lawmakers were asked to defend President Donald Trump’s immigration policies and provide a timeline on repealing and replacing the Affordable Care Act.

Now, many of them are skipping out on these events entirely. Some have said large meetings are an ineffective format for addressing individual concerns. Many others have, like the President himself, dismissed those questioning their agenda as “paid protesters” or radical activists who could pose a physical threat.

Voters turning out to town halls are pushing back hard on this characterization, arguing that they represent varied ideological backgrounds and have diverse issues to raise. Constituents unable to meet with their elected officials over the weekend told TPM that they’re not attending town hall events to make trouble. Instead, they say they want accountability from the people they pay to represent them.

Kim Mattoch, a mother of three and event planner, told TPM that she tried to go to a Saturday town hall in Roseville, California with GOP Rep. Tom McClintock but couldn’t make it in. The 200-seat theater hosting the event was quickly filled to capacity, leaving hundreds waiting outside.

“I’m a constituent of McClintock and a registered Republican in a very Republican district—though I don’t really align very well these days with the Republican Party,” Mattoch said in a Monday phone call. “So I wanted to go to the town hall because I legitimately had questions for the congressman.”

Mattoch said the protesters waiting outside had a wide range of “legitimate concerns.” She personally hoped to ask her representative about how the GOP was progressing on repealing and replacing the ACA and why House Republicans last week voted to kill a ruling aimed at preventing coal mining debris from ending up in waterways.

Yet McClintock told the Los Angeles Times that he thought an “anarchist element” was present in the crowd outside his event, and said he was escorted to his car by police because he’d been told the atmosphere was “deteriorating.”

Ramon Fliek, who attended the McClintock event with his wife, told TPM on Monday that police “were kind enough to block the whole road” to make space for the overflow crowd, and that he overheard protesters thanking law enforcement for “doing their jobs.”

“If you look at the videos from the event, you can’t get any notion that it was aggressive,” he said. “There was an older woman with a poodle that ran after him and it’s like, okay, the older lady with the poodle is not going to threaten you. I understand that he might want to give that impression, but it was very pleasant.”
Admittedly, it is a long time until midterms, but possibly not long enough to repair this kind of damage.

Saturday, December 9, 2017

Consequences of budget deficits

This is Joseph

Paul Krugman via Mark Thoma:
For budget deficits are going to soar thanks to Republican legislation — probably by even more than the official scorekeepers say, because the legislation creates so many new loopholes. And offsetting those deficits will require going after the true big-ticket programs, namely Medicare and Social Security.
Oh, they’ll find euphemisms to describe what they’re doing, talking solemnly about the need for “entitlement reform” as an act of fiscal responsibility — while their huge budget-busting tax cut for the rich gets shoved down the memory hole. But whatever words they use to cloak the reality of the situation, Republicans have given their donors what they wanted — and now they’re coming for your benefits.
I am actually a big opponent of "deficits don't matter", even when spouted by the left.  I totally understand the need to invest and that low interest rates that right now is a fine time to run deficits if there is a good reason.  But, in the long run, deficits either need to be paid or are going to act in an inflationary way.  What is saving us, for now, is that the rich are so rich that there are a shortage of secure investment opportunities so rates are low. 

But, in the long run, to spend is to tax.  All that reducing taxes now is doing is moving this taxing off into the future.  Or shifting the tax burden around, by future defaults on bonds (for example), which might target specific segments of the population. 

What I find hard to swallow is how the deficit language is swallowed by the media as if they are not able to follow the basics of the structure of the arguments.  If we use the (imperfect) household analogy, we are saying that we should reduce our income (taxes) and then discover that we need to reduce expenses, in world where there is plenty of income available. 

Now you could make a first principles argument for why social security and medicare are bad ideas (or perhaps defense, the other large item).  But that should be done in parallel with the cuts in income and not afterwards because of the cuts.  If a family decides that they no longer need a car, and thus can work less, the correct order is deciding to ditch the car and then deciding to cut back on work.  Not waiting for a crisis. 

I really wish that the reporting on this issue was more explicit. 

Friday, December 8, 2017

Adam ruins lab nice

Given the number of readers with relevant experience in this field, perhaps someone would like to weigh in on this.

Thursday, December 7, 2017


I'm a big fan of abstract strategy games, particularly those played on hexagonally-tiled boards (such as the ones you can purchase here). One of my favorites is Agon. It's a challenging but easy to learn game that's deserves a much bigger following. Here is the write-up I did of the rules a few years ago.

Agon may be the oldest abstract strategy game played on a 6 by 6 by 6 hexagonally tiled board, first appearing as early as the late Eighteenth Century in France. The game reached it greatest popularity a hundred years later when the Victorians embraced it for its combination of simple moves and complex strategy.

The Pieces: Each player has one queen and six pawns a.k.a. guards placed in the pattern indicated below
Agon Start

The Objective: To place your queen in the center hexagon and surround her with all six of her guards.(below)


Moves: Think of the Agon board as a series of concentric circles (see above). Pieces can move one space at a time either in the same ring or the ring closer to the center. In the figure on the left, a piece on a hexagon marked 4 could move to an adjacent hexagon marked either 4 or 3. Only the queen is allowed to move into the center hexagon. The figure below shows possible moves.


Capturing: A piece is captured when there are two enemy pieces on either side of it. The player with the captured piece must use his or her next move to place the captured piece on the outside hexagon.
If the captured piece is a guard, the player whose piece was captured can choose where on the outer hex to place the piece. If the piece is a queen, the player who made the capture decides where the queen should go.

If more than one piece is captured in one turn, the player whose pieces were captured must move them one turn at a time.

If a player surrounds the center hexagon with guards without getting the queen into position, that player forfeits the game.

Dilation and contraction.

Our standard narrative is deeply invested in the idea that progress is ever accelerating and that we are always on the cusp of an unimaginable leap forward. One of the favorite devices used to sustain this belief is dilation/contraction. The rate of technological change and its impact on society in the past is underestimated (particularly when describing the periods of the late 19th/early 20th centuries and the postwar era) while the current rate of change is overestimated, often wildly so when it comes to near-future predictions.

The following by Jim Hoagland is a good example.
Driverless cars and trucks rule the road, while robots “man” the factories. Super-smartphones hail Uber helicopters or even planes to fly their owners across mushrooming urban areas. Machines use algorithms to teach themselves cognitive tasks that once required human intelligence, wiping out millions of managerial, as well as industrial, jobs.

These are visions of a world remade — for the most part, in the next five to 10 years — by technological advances that form a fourth industrial revolution. You catch glimpses of the same visions today not only in Silicon Valley but also in Paris think tanks, Chinese electric-car factories or even here at the edge of the Sahara.

Technological disruption in the 21st century is different. Societies had years to adapt to change driven by the steam engine, electricity and the computer. Today, change is instant and ubiquitous. It arrives digitally across the globe all at once.

It is essential to note that, despite decades of serious and aggressive research and development, none of these technologies currently exist (at least not at the levels implied here) and, with the exception of autonomous vehicles, they probably won't exist a decade from now. Even with AVs, ruling the road will probably take decades unless we start heavily regulating non-autonomous cars.

(As we've pointed out before, there is an important distinction between driverless cars and driverless trucks. While both are coming, the current economic case for autonomous trucking makes far more sense and the technological challenge of driving a relatively small number of routes is considerably less. Long haul truck driving has the potential to go away quite suddenly.)

It's true that outside factors often slowed implementation in fields like electricity in the past. Factories had to be reconfigured. Power lines had to be laid. This meant that the adoption of certain technologies was delayed, particularly in certain localities, but even with this, the rate of technological change around the turn-of-the-century and, to a somewhat lesser extent, in the postwar era, was stunning.

More importantly in this case, (barring the special case where a new technology can be uploaded without any kind of change or upgrade of hardware) the same basic issues still apply. Even with AV's, there's still development time, infrastructure and adoption to consider.

The day is coming when you'll be able to say an address into your phone and have your car on its way without ever leaving the comfort of your couch. The prognosis for Hoagland's other just-around-the-corner innovations is considerably less promising. There are daunting problems involved with using AI to take over complex, badly understood tasks that largely lack reliable and agreed-upon metrics of success. While as for flying cars, the obstacles are huge and we have a history of failed promises going back literally a century. Just because some compulsive liar whose primary accomplishment has been getting gullible venture capitalists to write him ginormous checks makes this particular promise doesn't mean you should report it in the pages of the Washington Post as a done deal.

But even allowing for the vanishingly small chance that all of these things do come to pass roughly in the time frame given, we would still be nowhere near the level of technological change that people in the late 19th and early 20th centuries had to adapt to in virtually every aspect of their world, from day-to-day living to industry to transportation to mass media to telecommunications to medicine to agriculture and to all the others that I have invariably left off the list.

Wednesday, December 6, 2017

Insert obligatory what's-a-newspaper? joke here

Another small piece (or, more accurately, medium-size piece of a big piece) of the late 19th/early 20th century technology spike.

Media innovation was a big part of this story, not in the same league as internal combustion and electricity, but still a big player marked with a number of stunning advances.Most of the attention here tends to go to the then completely new developments such as recorded sound and moving pictures, but in terms of impact, advances in printing may have had more of an effect on the period.

I have been going through some old Scientific Americans for material and came across this excellent example from 1896. In the middle of the century, putting out a major metropolitan daily required the equivalent of a medium-size, well staffed factory.

By the last decade of the century, the presses were five times as fast, a fraction of the size, and largely automated.

This and other technological innovations (such as color printing) made publications like the Strand magazine and journalistic events like the Hearst/Pulitzer circulation wars and the rise of the comic strips possible. All of this had an enormous impact on American culture and politics.

Tuesday, December 5, 2017

Non-belated Tuesday Tweets

Monday, December 4, 2017

Want to see a 19th Century polar exploration balloon? Thought so...

Besancon and Hermite never actually made the trip, of course, but, damn, the illustrations are cool.

Friday, December 1, 2017

Yes, I know I've reposted this, but it keeps getting more relevant

Tuesday, August 22, 2017

The Republicans' 3 x 3 existential threat

I've argued previously that Donald Trump presents an existential threat to the Republican Party. I know this can sound overheated and perhaps even a bit crazy. There are few American institutions as long-standing and deeply entrenched as are the Democratic and Republican parties. Proposing that one of them might not be around 10 years from now beggars the imagination and if this story started and stopped with Donald Trump, it would be silly to suggest we were on the verge of  a political cataclysm.

But, just as Trump's rise did not occur in a vacuum, neither will his fall. We discussed earlier how Donald Trump has the power to drive a wedge between the Republican Party and a significant segment of its base [I wrote this before the departure of Steve Bannon. That may diminish Trump's ability to create this rift but I don't think it reduces the chances of the rift happening. – – M.P.]. This is the sort of thing that can profoundly damage a political party, possibly locking it into a minority status for a long time, but normally the wound would not be fatal. These, however, are not normal times.

The Republican Party of 2017 faces a unique combination of interrelated challenges, each of which is at a historic level and the combination of which would present an unprecedented threat to this or any US political party. The following list is not intended to be exhaustive, but it hits the main points.

The GOP currently has to deal with extraordinary political scandals, a stunningly unpopular agenda and daunting demographic trends. To keep things symmetric and easy to remember, let's break each one of these down to three components (keeping in mind that the list may change).

With the scandals:

1. Money – – Even with the most generous reading imaginable, there is no question that Trump has a decades long record of screwing people over, skirting the law, and dealing with disreputable and sometimes criminal elements. At least some of these dealings have been with the Russian mafia, oligarchs, and figures tied in with the Kremlin which leads us to…

2. The hacking of the election – – This one is also beyond dispute. It happened and it may have put Donald Trump into the White House. At this point, we have plenty of quid and plenty of quo; if Mueller can nail down pro, we will have a complete set.

3. And the cover-up – – As Josh Marshall and many others have pointed out, the phrase "it's not the crime; it's the cover-up" is almost never true. That said, coverups can provide tipping points and handholds for investigators, not to mention expanding the list of culprits.

With the agenda:

1. Health care – – By some standards the most unpopular major policy proposal in living memory that a party in power has invested so deeply in. Furthermore, the pushback against the initiative has essentially driven congressional Republicans into hiding from their own constituents for the past half year. As mentioned before, this has the potential to greatly undermine the relationship between GOP senators and representatives and the voters.

2. Tax cuts for the wealthy – – As said many times, Donald Trump has a gift for making the subtle plain, the plain obvious, and the obvious undeniable. In the past, Republicans were able to get a great deal of upward redistribution of the wealth past the voters through obfuscation and clever branding, but we have reached the point where simply calling something "tax reform" is no longer enough to sell tax proposals so regressive that even the majority of Republicans oppose them.

3. Immigration (subject to change) – – the race for third place in this list is fairly competitive (education seems to be coming up on the outside), but the administration's immigration policies (which are the direct result of decades of xenophobic propaganda from conservative media) have already done tremendous damage, caused great backlash, and are whitening the gap between the GOP and the Hispanic community, which leads us to…


As Lindsey Graham has observed, they simply are not making enough new old white men to keep the GOP's strategy going much longer, but the Trump era rebranding of the Republican Party only exacerbates the problems with women, young people, and pretty much anyone who isn't white.

Maybe I am missing a historical precedent here, but I can't think of another time that either the Democrats or the Republicans were this vulnerable on all three of these fronts. This does not mean that the party is doomed or even that, with the right breaks, it can't maintain a hold on some part of the government. What it does mean is that the institution is especially fragile at the moment. A mortal blow may not come, but we can no longer call it unthinkable.

Lots of threads converging on this one

And all of them tremendously important. Corruption and regulatory capture. An almost mystical faith in the magic of markets and private-enterprise approaches (even if they end up being all but completely government-subsidized). An inexhaustible tolerance for concentration of wealth and power. Internalized Randianism complete with the belief that the rest of us owe a debt to the rich and powerful that we can never fully repay. Regulatory capture and occasionally good old-fashioned corruption.

Thank God for John Oliver.

Thursday, November 30, 2017

I'm running behind again so...

Here are two beautiful French planes from 1909. Back tomorrow with actual prose.

And a few impressive airships.

Tuesday, November 28, 2017

Belated Tuesday Tweets


A few years ago, when I was teaching high school, I designed some games to illustrate mathematical concepts and develop strategic thinking and problem-solving skills. The clear winner in terms of player response was a game called Kruzno.

Despite the pieces (I decided to go with something off the shelf for the prototype), it's not a chess variant. Instead, it's a capture-and-evade abstract strategy game where the rank of the pieces is non-transitive. The rules are simple enough for a small child to play but challenging enough to keep reasonably competent chess players on their toes. It is also the official game of a small village in Slovakia, but that's a story for another time.

Between now and Christmas, I'll be writing some posts on game design and possibly sharing some thoughts and cautionary tales about jumping into a small business with no relevant experience. In the meantime, I still have some of that first run up for sale on Amazon. Go by and check it out.

Monday, November 27, 2017

Another Tesla article from the Scientific American archives (along with some very cool train pictures).

19th Century drawing of a Geissler tubes.

This story mainly stands on its own but there are a couple points I want to emphasize. First, it's a nice example of that distinctive Tesla combination: important innovator; savvy showmen; extravagantly over-promising flake. That's not just something that shows in retrospect; you can see it coming through contemporary accounts. Sober observers were well aware of all of these facets. The man was capable of amazing advances; he also reported getting messages from Mars.

I also like the way the story knocks down a false but persistent trope. There's a tendency to treat earlier generations as innocent and unimaginative, often oblivious to the extraordinary events that were starting to unfold. Call it the "little did they imagine" genre. The trouble is it's almost entirely wrong. Particularly in America, people in the late 19th and early 20th centuries saw themselves as living in a wondrous time and they tended to greet new developments with great excitement, if anything, often overestimating the degree to which their world was about to change.

Reading through these old articles, one thing that strikes me is that wildly ambitious ideas were not accepted unskeptically, but they weren't treated dismissively either. People seemed to get that an idea could fail miserably and still be of great value.

Friday, November 24, 2017

This is what a good job market looks like.

In the postwar era, employers (particularly what we would now call the stem fields) were genuinely hungry. They were willing to be flexible about qualifications and creative about recruiting.

What's My Line? (1950–1967)
Episode dated 20 February 1955