About That Apparent Decline in Violent Conflict…

Is violent conflict declining, or isn’t it? I’ve written here and elsewhere about evidence that warfare and mass atrocities have waned significantly in recent decades, at least when measured by the number of people killed in those episodes. Not everyone sees the world the same way, though. Bear Braumoeller asserts that, to understand how war prone the world is, we should look at how likely countries are to use force against politically relevant rivals, and by this measure the rate of warfare has held pretty steady over the past two centuries. Tanisha Fazal argues that wars have become less lethal without becoming less frequent because of medical advances that help keep more people in war zones alive. Where I have emphasized war’s lethal consequences, these two authors emphasize war’s likelihood, but their arguments suggest that violent conflict hasn’t really waned the way I’ve alleged it has.

This week, we got another important contribution to the wider debate in which my shallow contributions are situated. In an updated working paper, Pasquale Cirillo and Nassim Nicholas Taleb claim to show that

Violence is much more severe than it seems from conventional analyses and the prevailing “long peace” theory which claims that violence has declined… Contrary to current discussions…1) the risk of violent conflict has not been decreasing, but is rather underestimated by techniques relying on naive year-on-year changes in the mean, or using sample mean as an estimator of the true mean of an extremely fat-tailed phenomenon; 2) armed conflicts have memoryless inter-arrival times, thus incompatible with the idea of a time trend.

Let me say up front that I only have a weak understanding of the extreme value theory (EVT) models used in Cirillo and Taleb’s paper. I’m a political scientist who uses statistical methods, not a statistician, and I have neither studied nor tried to use the specific techniques they employ.

Bearing that in mind, I think the paper successfully undercuts the most optimistic view about the future of violent conflict—that violent conflict has inexorably and permanently declined—but then I don’t know many people who actually hold that view. Most of the work on this topic distinguishes between the observed fact of a substantial decline in the rate of deaths from political violence and the underlying risk of those deaths and the conflicts that produce them. We can (partly) see the former, but we can’t see the latter; instead, we have to try to infer it from the conflicts that occur. Observed history is, in a sense, a single sample drawn from a distribution of many possible histories, and, like all samples, this one is only a jittery snapshot of the deeper data-generating process in which we’re really interested. What Cirillo and Taleb purport to show is that long sequences of relative peace like the one we have seen in recent history are wholly consistent with a data-generating process in which the risk of war and death from it have not really changed at all.

Of course, the fact that a decades-long decline in violent conflict like the one we’ve seen since World War II could happen by chance doesn’t necessarily mean that it is happening by chance. The situation is not dissimilar to one we see in sports when a batter or shooter seems to go cold for a while. Oftentimes that cold streak will turn out to be part of the normal variation in performance, and the athlete will eventually regress to the mean—but not every time. Sometimes, athletes really do get and stay worse, maybe because of aging or an injury or some other life change, and the cold streak we see is the leading edge of that sustained decline. The hard part is telling in real time which process is happening. To try to do that, we might look for evidence of those plausible causes, but humans are notoriously good at spotting patterns where there are none, and at telling ourselves stories about why those patterns are occurring that turn out to be bunk.

The same logic applies to thinking about trends in violent conflict. Maybe the downward trend in observed death rates is just a chance occurrence in an unchanged system, but maybe it isn’t. And, as Andrew Gelman told Zach Beauchamp, the statistics alone can’t answer this question. Cirillo and Taleb’s analysis, and Braumoeller’s before it, imply that the history we’ve seen in the recent past  is about as likely as any other, but that fact isn’t proof of its randomness. Just as rare events sometimes happen, so do systemic changes.

Claims that “This time really is different” are usually wrong, so I think the onus is on people who believe the underlying risk of war is declining to make a compelling argument about why that’s true. When I say “compelling,” I mean an argument that a) identifies specific causal mechanisms and b) musters evidence of change over time in the presence or prevalence of those mechanisms. That’s what Steven Pinker tries at great length to do in The Better Angels of Our Nature, and what Joshua Goldstein did in Winning the War on War.

My own thinking about this issue connects the observed decline in the the intensity of violent conflict to the rapid increase in the past 100+ years in the size and complexity of the global economy and the changes in political and social institutions that have co-occurred with it. No, globalization is not new, and it certainly didn’t stop the last two world wars. Still, I wonder if the profound changes of the past two centuries are accumulating into a global systemic transformation akin to the one that occurred locally in now-wealthy societies in which organized violent conflict has become exceptionally rare. Proponents of democratic peace theory see a similar pattern in the recent evidence, but I think they are too quick to give credit for that pattern to one particular stream of change that may be as much consequence as cause of the deeper systemic transformation. I also realize that this systemic transformation is producing negative externalities—climate change and heightened risks of global pandemics, to name two—that could offset the positive externalities or even lead to sharp breaks in other directions.

It’s impossible to say which, if any, of these versions is “true,” but the key point is that we can find real-world evidence of mechanisms that could be driving down the underlying risk of violent conflict. That evidence, in turn, might strengthen our confidence in the belief that the observed pattern has meaning, even if it doesn’t and can’t prove that meaning or any of the specific explanations for it.

Finally, without deeply understanding the models Cirillo and Taleb used, I also wondered when I first read their new paper if their findings weren’t partly an artifact of those models, or maybe some assumptions the authors made when specifying them. The next day, David Roodman wrote something that strengthened this source of uncertainty. According to Roodman, the extreme value theory (EVT) models employed by Cirillo and Taleb can be used to test for time trends, but the ones described in this new paper don’t. Instead, Cirillo and Taleb specify their models in a way that assumes there is no time trend and then use them to confirm that there isn’t. “It seems to me,” Roodman writes, “that if Cirillo and Taleb want to rule out a time trend according to their own standard of evidence, then they should introduce one in their EVT models and test whether it is statistically distinguishable from zero.”

If Roodman is correct on this point, and if Cirillo and Taleb were to do what he recommends and still find no evidence of a time trend, I would update my beliefs accordingly. In other words, I would worry a little more than I do now about the risk of much larger and deadlier wars occurring again in my expected lifetime.

An Applied Forecaster’s Bad Dream

This is the sort of thing that freaks me out every time I’m getting ready to deliver or post a new set of forecasts:

In its 2015 States of Fragility report, the Organization for Economic Co-operation and Development (OECD) decided to complicate its usual one-dimensional list of fragile states by assessing five dimensions of fragility: Violence, Justice, Institutions, Economic Foundations and Resilience…

Unfortunately, something went wrong during the calculations. In my attempts to replicate the assessment, I found that the OECD misclassified a large number of states.

That’s from a Monkey Cage post by Thomas Leo Scherer, published today. Here, per Scherer, is why those errors matter:

Recent research by Judith Kelley and Beth Simmons shows that international indicators are an influential policy tool. Indicators focus international attention on low performers to positive and negative effect. They cause governments in poorly ranked countries to take action to raise their scores when they realize they are being monitored or as domestic actors mobilize and demand change after learning how they rate versus other countries. Given their potential reach, indicators should be handled with care.

For individuals or organizations involved in scientific or public endeavors, the best way to mitigate that risk is transparency. We can and should argue about concepts, measures, and model choices, but given a particular set of those elements, we should all get essentially the same results. When one or more of those elements is hidden, we can’t fully understand what the reported results represent, and researchers who want to improve the design by critiquing and perhaps extending it are forced to box shadows. Also, individuals and organizations can double– and triple-check their own work, but errors are almost inevitable. When getting the best possible answers matters more than the risk of being seen making mistakes, then transparency is the way to go. This is why the Early Warning Project shares the data and code used to produce its statistical risk assessments in a public repository, and why Reinhart and Rogoff probably (hopefully?) wish they’d done something similar.

Of course, even though transparency improves the probability of catching errors and improving on our designs, it doesn’t automatically produce those goods. What’s more, we can know that we’re doing the right thing and still dread the public discovery of an error. Add to that risk the near-certainty of other researchers scoffing at your terrible code, and it’s easy see why even the best practices won’t keep you from breaking out in a cold sweat each time you hit “Send” or “Publish” on a new piece of work.

 

Polity Meets Joy Division

The Center for Systemic Peace posted its annual update of the Polity data set on Friday, here. The data set now covers the period 1800–2014.

For those of you who haven’t already fled the page to go download the data and who aren’t political scientists: Polity measures patterns of political authority in all countries with populations larger than 500,000. It is one of the mostly widely used data sets in the fields of comparative politics and international relations. Polity is also tremendously useful in forecasts of rare political crises—partly because it measures some very important things, but also because it is updated every year on a fairly predictable schedule. Thanks to PITF and CSP for that.

I thought I would mark the occasion by visualizing Polity in a new way (for me, at least). In the past, I’ve used heat maps (here and here) and line plots of summary statistics. This time, I wanted to try something other than a heat map that would show change over time in a distribution, instead of just a central tendency. Weakly inspired by the often-imitated cover of Joy Division’s 1979 album, here’s what I got. Each line in this chart is a kernel density plot of one year’s Polity scores, which range from -10 to 10 and are meant to indicate how democratic a country’s politics are. The small number of cases with special codes that don’t fit on this scale (-66, -77, and -88) have been set aside.

polity.meets.joy.division

The chart shows once again that the world has become much more democratic in the past half-century, with most of those gains occurring in the past 30 years. In the early 1960s, the distribution of national political regimes was bimodal, but authoritarian regimes outnumbering the more-democratic ones. As recently as the early 1970s, most regimes still fell toward the authoritarian end of the scale. Starting in the late 1980s, though, the authoritarian peak eroded quickly, and the balance of the distribution shifted toward the democratic end. Despite continuing talk of a democratic recession, the (political) world in 2014 is still mostly composed of relatively democratic regimes, and this data set doesn’t show much change in that basic pattern over the past decade.

 

The Myth of Comprehensive Data

“What about using Twitter sentiment?”

That suggestion came to me from someone at a recent Data Science DC meetup, after I’d given a short talk on assessing risks of mass atrocities for the Early Warning Project, and as the next speaker started his presentation on predicting social unrest. I had devoted the first half of my presentation to a digression of sorts, talking about how the persistent scarcity of relevant public data still makes it impossible to produce global forecasts of rare political crises—things like coups, insurgencies, regime breakdowns, and mass atrocities—that are as sharp and dynamic as we would like.

The meetup wasn’t the first time I’d heard that suggestion, and I think all of the well-intentioned people who have made it to me have believed that data derived from Twitter would escape or overcome those constraints. In fact, the Twitter stream embodies them. Over the past two decades, technological, economic, and political changes have produced an astonishing surge in the amount of information available from and about the world, but that surge has not occurred evenly around the globe.

Think of the availability of data as plant life in a rugged landscape, where dry peaks are places of data scarcity and fertile valleys represent data-rich environments. The technological developments of the past 20 years are like a weather pattern that keeps dumping more and more rain on that topography. That rain falls unevenly across the landscape, however, and it doesn’t have the same effect everywhere it lands. As a result, plants still struggle to grow on many of those rocky peaks, and much of the new growth occurs where water already collected and flora were already flourishing.

The Twitter stream exemplifies this uneven distribution of data in a couple of important ways. Take a look at the map below, a screenshot I took after letting Tweetping run for about 16 hours spanning May 6–7, 2015. The brighter the glow, the more Twitter activity Tweetping saw.

tweetping 1530 20150506 to 0805 20150507

Some of the spatial variation in that map reflects differences in the distribution of human populations, but not all of it. Here’s a map of population density, produced by Daysleeper using data from CEISIN (source). If you compare this one to the map of Twitter usage, you’ll see that they align pretty well in Europe, the Americas, and some parts of Asia. In Africa and other parts of Asia, though, not so much. If it were just a matter of population density, then India and eastern China should burn brightest, but they—and especially China—are relatively dark compared to “the West.” Meanwhile, in Africa, we see pockets of activity, but there are whole swathes of the continent that are populated as or more densely than the brighter parts of South America, but from which we see virtually no Twitter activity.

world population density map

So why are some pockets of human settlement less visible than others? Two forces stand out: wealth and politics.

First and most obvious, access to Twitter depends on electricity and telecommunications infrastructure and gadgets and literacy and health and time, all of which are much scarcer in poorer parts of the world than they are in richer places. The map below shows lights at night, as seen from space by U.S. satellites 20 years ago and then mapped by NASA (source). These light patterns are sometimes used as a proxy for economic development (e.g., here).

earth_lights

This view of the world helps explain some of the holes in our map of Twitter activity, but not all of it. For example, many of the densely populated parts of Africa don’t light up much at night, just as they don’t on Tweetping, because they lack the relevant infrastructure and power production. Even 20 years ago, though, India and China looked much brighter through this lens than they do on our Twitter usage map.

So what else is going on? The intensity and character of Twitter usage also depends on freedoms of information and speech—the ability and desire to access the platform and to speak openly on it—and this political layer keeps other areas in the dark in that Tweetping map. China, North Korea, Cuba, Ethiopia, Eritrea—if you’re trying to anticipate important political crises, these are all countries you would want to track closely, but Twitter is barely used or unavailable in all of them as a direct or indirect consequence of public policy. And, of course, there are also many places where Twitter is accessible and used but censorship distorts the content of the stream. For example, Saudi Arabia lights up pretty well on the Twitter-usage map, but it’s hard to imagine people speaking freely on it when a tweet can land you in prison.

Clearly, wealth and political constraints still strongly shape the view of the world we can get from new data sources like Twitter. Contrary to the heavily-marketed myth of “comprehensive data,” poverty and repression continue to hide large swathes of the world out of our digital sight, or to distort the glimpses we get of them.

Unfortunate for efforts to forecast rare political crises, those two structural features that so strongly shape the production and quality of data also correlate with the risks we want to anticipate. The map below shows the Early Warning Project‘s most recent statistical assessments of the risk of onsets of state-led mass-killing episodes. Now flash back to the visualization of Twitter usage above, and you’ll see that many of the countries colored most brightly on this map are among the darkest on that one. Even in 2015, the places about which we most need more information to sharpen our forecasts of rare political crises are the ones that are still hardest to see.

ewp.sra.world.2014

Statistically, this is the second-worst of all possible worlds, the worst one being the total absence of information. Data are missing not at random, and the processes producing those gaps are the same ones that put places at greater risk of mass atrocities and other political calamities. This association means that models we estimate with those data will often be misleading. There are ways to mitigate these problems, but they aren’t necessarily simple, cheap, or effective, and that’s before we even start in on the challenges of extracting useful measures from something as heterogeneous and complex as the Twitter stream.

So that’s what I see when I hear people suggest that social media or Google Trends or other forms of “digital exhaust” have mooted the data problems about which I so often complain. Lots of organizations are spending a lot of money trying to overcome these problems, but the political and economic topography producing them does not readily yield. The Internet is part of this complex adaptive system, not a space outside it, and its power to transform that system is neither as strong nor as fast-acting as many of us—especially in the richer and freer parts of the world—presume.

To Realize the QDDR’s Early-Warning Goal, Invest in Data-Making

The U.S. Department of State dropped its second Quadrennial Diplomacy and Development Review, or QDDR, last week (here). Modeled on the Defense Department’s Quadrennial Defense Review, the QDDR lays out the department’s big-picture concerns and objectives so that—in theory—they can guide planning and shape day-to-day decision-making.

The new QDDR establishes four main goals, one of which is to “strengthen our ability to prevent and respond to internal conflict, atrocities, and fragility.” To help do that, the State Department plans to “increase [its] use of early warning analysis to drive early action on fragility and conflict.” Specifically, State says it will:

  1. Improve our use of tools for analyzing, tracking, and forecasting fragility and conflict, leveraging improvements in analytical capabilities;
  2. Provide more timely and accurate assessments to chiefs of mission and senior decision-makers;
  3. Increase use of early warning data and conflict and fragility assessments in our strategic planning and programming;
  4. Ensure that significant early warning shifts trigger senior-level review of the mission’s strategy and, if necessary, adjustments; and
  5. Train and deploy conflict-specific diplomatic expertise to support countries at risk of conflict or atrocities, including conflict negotiation and mediation expertise for use at posts.

Unsurprisingly, that plan sounds great to me. We can’t now and never will be able to predict precisely where and when violent conflict and atrocities will occur, but we can assess risks with enough accuracy and lead time to enable better strategic planning and programming. These forecasts don’t have to be perfect to be earlier, clearer, and more reliable than the traditional practices of deferring to individual country or regional analysts or just reacting to the news.

Of course, quite a bit of well-designed conflict forecasting is already happening, much of it paid for by the U.S. government. To name a few of the relevant efforts: The Political Instability Task Force (PITF) and the Worldwide Integrated Conflict Early Warning System (W-ICEWS) routinely update forecasts of various forms of political crisis for U.S. government customers. IARPA’s Open Source Indicators (OSI) and Aggregative Contingent Estimation (ACE) programs are simultaneously producing forecasts now and discovering ways to make future forecasts even better. Meanwhile, outside the U.S. government, the European Union has recently developed its own Global Conflict Risk Index (GCRI), and the Early Warning Project now assesses risks of mass atrocities in countries worldwide.

That so much thoughtful risk assessment is being done now doesn’t mean it’s a bad idea to start new projects. If there are any iron laws of forecasting hard-to-predict processes like political violence, one of them is that combinations of forecasts from numerous sources should be more accurate than forecasts from a single model or person or framework. Some of the existing projects already do this kind of combining themselves, but combinations of combinations will often be even better.

Still, if I had to channel the intention expressed in this part of the QDDR into a single activity, it would not be the construction of new models, at least not initially. Instead, it would be data-making. Social science is not Newtonian physics, but it’s not astrology, either. Smart people have been studying politics for a long time, and collectively they have developed a fair number of useful ideas about what causes or precedes violent conflict. But, if you can’t track the things those theorists tell you to track, then your forecasts are going to suffer. To improve significantly on the predictive models of political violence we have now, I think we need better inputs most of all.

When I say “better” inputs, I have a few things in mind. In some cases, we need to build data sets from scratch. When I was updating my coup forecasts earlier this year, a number of people wondered why I didn’t include measures of civil-military relations, which are obviously relevant to this particular risk. The answer was simple: because global data on that topic don’t exist. If we aren’t measuring it, we can’t use it in our forecasts, and the list of relevant features that falls into this set is surprisingly long.

In other cases, we need to revive them. Social scientists often build “boutique” data sets for specific research projects, run the tests they want to run on them, and then move on to the next project. Sometimes, the tests they or others run suggest that some features captured in those data sets would make useful predictors. Those discoveries are great in principle, but if those data sets aren’t being updated, then applied forecasters can’t use that knowledge. To get better forecasts, we need to invest in picking up where those boutique data sets left off so we can incorporate their insights into our applications.

Finally and in almost all cases, we need to observe things more frequently. Most of the data available now to most conflict forecasters is only updated once each year, often on a several-month delay and sometimes as much as two years later (e.g., data describing 2014 becomes available in 2016). That schedule is fine for basic research, but it is crummy for applied forecasting. If we want to be able to give assessments and warnings that as current as possible to those “chiefs of mission and senior decision-makers” mentioned in the QDDR, then we need to build models with data that are updated as frequently as possible. Daily or weekly are ideal, but monthly updates would suffice in many cases and would mark a huge improvement over the status quo.

As I said at the start, we’re never going to get models that reliably tell us far in advance exactly where and when violent conflicts and mass atrocities will erupt. I am confident, however, that we can assess these risks even more accurately than we do now, but only if we start making more, and better versions, of the data our theories tell us we need.

I’ll end with a final plea to any public servants who might be reading this: if you do invest in developing better inputs, please make the results freely available to the public. When you share your data, you give the crowd a chance to help you spot and fix your mistakes, to experiment with various techniques, and to think about what else you might consider, all at no additional cost to you. What’s not to like about that?

An Updated Look at Trends in Political Violence

The Center for Systemic Peace (CSP) has just posted an updated version of its Major Episodes of Political Violence data set, which now covers the period 1946-2014. That data set includes scalar measures of the magnitude of several forms of political violence between and within states. Per the codebook (PDF):

Magnitude scores reflect multiple factors including state capabilities, interactive intensity (means and goals), area and scope of death and destruction, population displacement, and episode duration. Scores are considered to be consistently assigned (i.e., comparable) across episode types and for all states directly involved.

For each country in each year, the magnitude scores range from 0 to 10. The chart below shows annual global sums of those scores for conflicts between and within states (i.e., the INTTOT and CIVTOT columns in the source data).

mepv.intensity.by.year

Consistent with other measures, CSP’s data show an increase in violent political conflict in the past few years. At the same time, those data also indicate that, even at the end of 2014, the scale of conflict worldwide remained well below the peak levels observed in the latter decades of the Cold War and its immediate aftermath. That finding provides no comfort to the people directly affected by the fighting ongoing today. Still, it should (but probably won’t) throw another blanket over hyperbolic statements about the world being more unstable than ever before.

If we look at the trends by region, we see what most avid newsreaders would expect to see. The chart below uses the U.S. State Department’s regional designations. It confirms that the recent increase in conflict within states (the orange lines) has mostly come from Africa and the Middle East. Conflicts persist in the Americas and East and South Asia, but their magnitude has generally diminished in recent years. Europe and Eurasia supplies the least violent conflict of any region, but the war in Ukraine—designated a civil conflict by this source and assigned a magnitude score of 2—increased that supply in 2014.

mepv.intensity.by.year.and.region

CSP saw almost no interstate conflict around the world in 2014. The global score of 1 accrues from U.S. operations in Afghanistan. When interstate conflict has occurred in the post–Cold War period, it has mostly come from Africa and the Middle East, too, but East Asia was also a major contributor as recently as the 1980s.

For a complete list of the episodes of political violence observed by CSP in this data set, go here. For CSP’s analysis of trends in these data, go here.

Walling Ourselves Off

In the past two weeks, more than a thousand people have died trying to cross the Mediterranean Sea from Africa to Europe on often-overloaded boats. In 2014, more than three thousand perished on this crossing.

Each individual migrant’s motives are unique and unknowable, but this collective surge in deaths clearly stems, in part, from the disorder engulfing parts of North Africa and the Middle East. Civil war and state collapse have expanded the incentives and opportunities to flee, and the increased flow of migrants along dangerous routes has, predictably, led to a surge in accidental deaths.

Of course, those deaths also owe something to the policies of the countries toward which the overloaded boats sail. European governments—many of them presiding over anemic growth and unemployment crises of their own—do not have open borders, and they have responded ambivalently or coolly to this spate of arrivals. Italy, where many of these boats land, had run a widely praised search-and-rescue program for a couple of years, but that effort was replaced in late 2014 by a smaller and so-far less successful EU program. Most observers lament the drownings, but some also worry that a more effective rescue scheme will encourage more people to attempt the crossing, or to get into the sordid business of ferrying others.

Humans have always, and often literally, built walls to keep outsiders out. Leslie Chang’s Factory Girls examines China’s current wave of urban migration, but she also dug into her own family’s history in that country and found this:

In 1644, the Manchus, an ethnic group living on China’s northeaster frontier, conquered China and established the Qing Dynasty. Soon thereafter, the Qing rulers declared Manchuria off-limits to the Han Chinese, the majority ethnic group of the rest of the country. Their aim was to monopolize the region’s natural resources and to preserve their homeland: As long as the frontier remained intact, they believed, their people would retain their vitality and forestall the corruption and decadence by which dynasties inevitably fell. To seal off Manchuria, the emperors ordered the construction of a two-hundred-mile mud wall planted with willow trees. It stretched from the Great Wall northeast through most of present-day Liaoning and Jilin provinces, with fortified checkpoints along its length.

The border was called the Willow Palisade, and it was even more porous than the Great Wall. It was completed in 1681, and perhaps twenty years later my ancestor breached it to settle in Liutai, which means “sixth post”—one of the fortified towers that was built expressly to keep out people like him.

An article by Sarah Stillman in this week’s New Yorker describes how, over the past 15 years, the U.S. has adopted tougher measures to keep migrants from crossing illegally into the U.S. from Mexico in spite of the U.S. economy’s continued dependence on more immigrant labor than our government will legally allow to enter. These measures, which include the construction of hundreds of miles of fence, apparently have slowed the rate of illegal crossings. At the same time, they have encouraged the expansion of the human-smuggling business, catalyzed the growth of criminal rackets that extort the families of kidnapped migrants for ransom, and, as in the Mediterranean, contributed to a significant increase in the number of deaths occurring en route.

On the US-Mexico border. Photo by Anthony Suau for TIME.

This impulse is not specific to rich countries. In South Africa, at least seven people have been killed this month in violent attacks on immigrants and their businesses in parts of Durban and Johannesburg. Among the governments publicly condemning these attacks is Nigeria’s. In the early 1980s, the Nigerian government expelled millions of West African migrants from its territory, “blaming them for widespread unemployment and crime” after a slump in oil prices pushed Nigeria’s economy into a downward spiral.

This impulse runs deep. A study published in 1997 found that drivers at a shopping mall left their parking spaces more slowly when another car was waiting near that space than they did when no one was around, even though that delay was costly for both parties. The study’s authors attributed that finding to territorial behavior—”marking or defending a location in order to indicate a presumed right to a particular place.”

This behavior may be instinctual, but that doesn’t mean it’s just. Physical or legal, these walls implicitly assign different values to the lives of the people on either side of them. According to liberalism—and to many other moral philosophies—this gradation of human life is wrong. We should not confuse the accident of our birth on the richer or safer side of those walls with a moral right to exclusively enjoy that relative wealth or safety. The intended and unintended consequences of policy change need to be considered alongside the desired end state, but they should at least be considered. The status quo is shameful.

Some economists also argue that the status quo is unnecessarily costly. In a 2011 paper in the Journal of Economic Perspectives, Michael Clemens estimated that barriers to emigration have a much larger damping effect on the global economy than barriers to capital and trade do.

How large are the economic losses caused by barriers to emigration? Research on this question has been distinguished by its rarity and obscurity, but the few estimates we have should make economists’ jaws hit their desks. When it comes to policies that restrict emigration, there appear to be trillion-dollar bills on the sidewalk.

I hope I live to see that claim tested.

Waiting for Data-dot

A suburban house. A desk cluttered with papers, headphones, stray cables, and a pair of socks. Dawn.

Jay, sitting at the desk, opens a browser tab and clicks on a favorited site to see if a data set he needs to produce forecasts has been updated yet. It has not. He pauses, slurps coffee from a large mug, and tries another site. As before.

JAY: (giving up again). Nothing to be done.

 

[Apologies to Samuel Beckett.]

 

 

A Bit More on Country-Month Modeling

My family is riding the flu carousel right now, and my turn came this week. So, in lieu of trying to write from scratch, I wanted to pick up where my last post—on moving from country-year to country-month modeling—left off.

As many of you know, this notion is hardly new. For at least the past decade, many political scientists who use statistical tools to study violent conflict have been advocating and sometimes implementing research designs that shrink their units of observation on various dimensions, including time. The Journal of Conflict Resolution published a special issue on “disaggregating civil war” in 2009. At the time, that publication felt (to me) more like the cresting of a wave of new work than the start of one, and it was motivated, in part, by frustration over all the questions that a preceding wave of country-year civil-war modeling had inevitably left unanswered. Over the past several years, Mike Ward and his WardLab collaborators at Duke have been using ICEWS and other higher-resolution data sets to develop predictive models of various kinds of political instability at the country-month level. Their work has used designs that deal thoughtfully with the many challenges this approach entails, including spatial and temporal interdependence and the rarity of the events of interest. So have others.

Meanwhile, sociologists who study protests and social movements have been pushing in this direction even longer. Scholars trying to use statistical methods to help understand the dynamic interplay between mobilization, activism, repression, and change recognized that those processes can take important turns in weeks, days, or even hours. So, researchers in that field started trying to build event data sets that recorded as exactly as possible when and where various actions occurred, and they often use event history models and other methods that “take time seriously” to analyze the results. (One of them sat on my dissertation committee and had a big influence on my work at the time.)

As far as I can tell, there are two main reasons that all research in these fields hasn’t stampeded in the direction of disaggregation, and one of them is a doozy. The first and lesser one is computing power. It’s no simple thing to estimate models of mutually causal processes occurring across many heterogeneous units observed at high frequency. We still aren’t great at it, but accelerating improvements in computational processing, storage, software—and co-evolving improvements in statistical methods—have made it more tractable than it was even five or 10 years ago.

The second, more important, and more persistent impediment to disaggregated analysis is data, or the lack thereof. Data sets used by statistically minded political scientists come in two basic flavors: global, and case– or region-specific. Almost all of the global data sets of which I’m aware have always used, and continue to use, country-years as their units of observation.

That’s partly a function of the research questions they were built to help answer, but it’s also a function of cost. Data sets were (and mostly still are) encoded by hand by people sifting through or poring over relevant documents. All that labor takes a lot of time and therefore costs a lot of money. One can make (or ask RAs to make) a reasonably reliable summary judgment about something like whether or not a civil war was occurring in a particular country during particular year much quicker than one can do that for each month of that year, or each district in that country, or both. This difficulty hasn’t stopped everyone from trying, but the exceptions have been few and often case-specific. In a better world, we could have patched together those case-specific sets to make a larger whole, but they often use idiosyncratic definitions and face different informational constraints, making cross-case comparison difficult.

That’s why I’ve been so excited about the launch of GDELT and Phoenix and now the public release of the ICEWS event data. These are, I think, the leading edge of efforts to solve those data-collection problems in an efficient and durable way. ICEWS data have been available for several years to researchers working on a few contracts, but they haven’t been accessible to most of us until now.  At first I thought GDELT had rendered that problem moot, but concerns about its reliability have encouraged me to keep looking. I think Phoenix’s open-source-software approach holds more promise for the long run, but, as its makers describe, it’s still in “beta release” and “under active development.” ICEWS is a more mature project that has tried carefully to solve some of the problems, like event duplication and errors in geolocation, that diminish GDELT’s utility. (Many millions of dollars help.) So, naturally, I and many others have been eager to start exploring it. And now we can. Hooray!

To really open up analysis at this level, though, we’re going to need comparable and publicly (or at least cheaply) available data sets on a lot more of things our theories tell us to care about. As I said in the last post, we have a few of those now, but not many. Some of the work I’ve done over the past couple of years—this, especially—was meant to help fill those gaps, and I’m hoping that work will continue. But it’s just a drop in a leaky bucket. Here’s hoping for a hard turn of the spigot.

Down the Country-Month Rabbit Hole

Some big things happened in the world this week. Iran and the P5+1 agreed on a framework for a nuclear deal, and the agreement looks good. In a presidential election in Nigeria—the world’s seventh–most populous country, and one that few observers would have tagged as a democracy before last weekend—incumbent Goodluck Jonathan lost and then promptly and peacefully conceded defeat. The trickle of countries joining China’s new Asian Infrastructure Investment Bank turned into a torrent.

All of those things happened, but you won’t read more about them here, because I have spent the better part of the past week down a different rabbit hole. Last Friday, after years of almosts and any-time-nows, the event data produced for the Integrated Conflict Early Warning System (ICEWS) finally landed in the public domain, and I have been busy trying to figure out how to put them to use.

ICEWS isn’t the first publicly available trove of political event data, but it compares favorably to the field’s first mover, GDELT, and it currently covers a much longer time span than the other recent entrant, Phoenix.

The public release of ICEWS is exciting because it opens the door wider to dynamic modeling of world politics. Right now, nearly all of the data sets employed in statistical studies of politics around the globe use country-years as their units of observation. That’s not bad if you’re primarily interested in the effects or predictive power of structural features, but it’s pretty awful for explaining and anticipating faster-changing phenomena, like social unrest or violent conflict. GDELT broke the lock on that door, but its high noise-to-signal ratio and the opacity of its coding process have deterred me from investing too much time in developing monitoring or forecasting systems that depend on it.

With ICEWS on the Dataverse, that changes. I think we now have a critical mass of data sets in the public domain that: a) reliably cover important topics for the whole world over many years; b) are routinely updated; and, crucially, c) can be parsed to the month or even the week or day to reward investments in more dynamic modeling. Other suspects fitting this description include:

  • The spell-file version of Polity, which measures national patterns of political authority;
  • Lists of coup attempts maintained by Jonathan Powell and Clayton Thyne (here) and the Center for Systemic Peace (here); and
  • The PITF Worldwide Atrocities Event Dataset, which records information about events involving the deliberate killing of five or more noncombatant civilians (more on it here).

We also have high-quality data sets on national elections (here) and leadership changes (here, described here) that aren’t routinely updated by their sources but would be relatively easy to code by hand for applied forecasting.

With ICEWS, there is, of course, a catch. The public version of the project’s event data set will be updated monthly, but on a one-year delay. For example, when the archive was first posted in March, it ran through February 2014. On April 1, the Lockheed team added March 2014. This delay won’t matter much for scholars doing retrospective analyses, but it’s a critical flaw, if not a fatal one, for applied forecasters who can’t afford to pay—what, probably hundreds of thousands of dollars?—for a real-time subscription.

Fortunately, we might have a workaround. Phil Schrodt has played a huge role in the creation of the field of machine-coded political event data, including GDELT and ICEWS, and he is now part of the crew building Phoenix. In a blog post published the day ICEWS dropped, Phil suggested that Phoenix and ICEWS data will probably look enough alike to allow substituting the former for the latter, perhaps with some careful calibration. As Phil says, we won’t know for sure until we have a wider overlap between the two and can see how well this works in practice, but the possibility is promising enough for me to dig in.

And what does that mean? Well, a week has now passed since ICEWS hit the Dataverse, and so far I have:

  • Written an R function that creates a table of valid country-months for a user-specified time period, to use as scaffolding in the construction and agglomeration of country-month data sets;
  • Written scripts that call that function and some others to ingest and then parse or aggregate the other data sets I mentioned to the country-month level;
  • Worked out a strategy, and written the code, to partition the data into training and test sets for a project on predicting violence against civilians; and
  • Spent a lot of time staring at the screen thinking about, and a little time coding, ways to aggregate, reduce, and otherwise pre-process the ICEWS events and Polity data for that work on violence against civilians and beyond.

What I haven’t done yet—T plus seven days and counting—is any modeling. How’s that for push-button, Big Data magic?

Follow

Get every new post delivered to your Inbox.

Join 12,572 other followers

%d bloggers like this: