Thursday, September 15, 2005

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Follow up on the commercial peace -- Gartzke replies to Rummel

Erik Gartzke sends along his reponse to R.J. Rummel's critique of his chapter "Economic Freedom and Peace" in Cato's 2005 annual report on Economic Freedom in the World. (click here and here for my previous blog posts on this topic.

I've put Gartzke's reply after the jump, because it's on the longish side and may bore non-IR types. I will, say, however, that the reply addresses many of the concerns I had about the study.

[So did you send it out for external review?--ed. Alas, no -- Erik can't count this as a refereed publication. It should count for something, though.]

UPDATE: Rummel replies here.


by Erik Gartzke

In a recent blog post titled “The CATO Institute Gets It All Wrong” posted on his webpage, Dr. R.J. Rummel presented some rather intense criticism of my recent chapter “Economic Freedom and Peace” in the 2005 edition of Economic Freedom of the World. I offer this note as a reply.

Dr. Rummel claims that I am wrong to write that “researchers have found that democracies are less likely to fight each other, while being no less ready to use force generally.” This is what other researchers have found. In fact, it is what most proponents of the democratic peace claim to show. Dr. Rummel knows that the majority of studies by democratic peace proponents do not support the assertion that democracies are generally less warlike (Rousseau, et al. 1996). Indeed, he has advocated the strong claim that democracies are generally pacific, in opposition to other proponents of the democratic peace. This difference of views within the democratic peace research community is not made clear in Dr. Rummel’s comments and may confuse his readers.

The comment that Dr. Rummel objects to thus simply summarizes the dominant view among democratic peace researchers. As Huth and Allee put it “patterns of military conflict between democracies and non-democracies are not very different from patterns of military conflict among non-democracies” (page 1, 2002). Bruce Russett, the dean of quantitative democratic peace researchers acknowledges that there is “little systematic evidence” in support of the claim that democracies are generally less warlike (page 11, 1993). Together, Russett and his research partner John Oneal, state that, “Our analyses clearly reveal the separate peace among democratic states” (page 288, 1997). There are many other examples. I quote the wikipedia encyclopedia:

Democratic peace theorists make two possible connections between democracy and war:

Babst, Singer, Rummel and Doyle claimed that democracies, properly defined, have never made war on each other; such DPTs face the difficulty that Ted Gurr classes both Spain and the United States as democracies in 1898, the year of the Spanish-American War.

Most more recent studies assert that two democracies are less likely to make war on each other than other pairs of states.

Thus, even if one admires Dr. Rummel’s research, it is simply not correct for him to suggest that I have mischaracterized the literature. Further, he does not make clear why I should adhere to his version of democratic peace when he has failed, despite vigorous efforts, to persuade other democratic peace researchers to do so. As a critic, I must address the most widely used version of an argument, or risk being attacked for setting up a “straw man.” In fact, by using the special dyadic claim of democratic peace, I am able to acknowledge that the study in question does not directly contradict the claims of dyadic researchers, though of course my findings also do not support the assertions of those who make the strong claim that democracies are generally more peaceful. (In other research, my results seem to show that even the weaker, dyadic version of democratic peace is not sustained when any of several measures of capitalist development and market integration are included in the analysis, but this is a discussion for another time.)

Dr. Rummel argues that I am doing democratization injustice by using the term “impose.” He suggests no alternative term, but references another blog post titled “Unchaining Human Rights, Not Imposing Democracy.” Certainly, “unchaining” sounds more affirmative, just as “freedom fighter” sounds more affirmative than “terrorist.” By “imposed,” I meant situations like Iraq, where democracy has not evolved endogenously. In Iraq, for example, unless democratic peace exists and is general (monadic), there can be no robust effect of democratization because other states in the region (besides Israel and Turkey) are not democracies. Research by Hegre (2004) shows that increasing democracy when few states are democratic tends to increase, not decrease, conflict. Even many advocates of democratic peace doubt that democratization in the Middle East will lead to peace in anything but the very long run. This, of course, also requires that we assume that US efforts to democratize Iraq will succeed, a debatable claim in its own right.

Dr. Rummel takes my study to task because I point out that the democratic peace observation has recently been limited to prosperous states. Here again, I am simply reporting the evolving consensus of democratic peace researchers themselves. Mousseau (2000) and Hegre (2000) report that an interaction term between variables for democracy and economic development leads the democracy term to become no longer statistically significant. In a newer study, John Oneal himself collaborates with Mousseau and Hegre in further substantiating this conclusion. As the result makes clear, democratic peace, if it exists, is conditioned by economic development. My view is that it is development itself, along with economic liberalization, that explains the peace.

Dr. Rummel claims that my assertions are falsified in my own data. As evidence, he argues that there are no “wars” between democracies. The specific claims that I make, and the data that I use involve militarized interstate disputes (MIDs), a broader category of conflict behavior. Wars are very rare. There are just 44 state participations in wars beginning in 1970, the earliest date for which the Index of Economic Freedom supplies data. Less than 1% of state years (think “man hours”) involve a war. For this reason, democratic peace researchers and others studying conflict among nations have overwhelmingly preferred in recent years to examine MIDs.

Still, it is not difficult to have a look. I examined the Correlates of War project listing of wars (conflicts involving at least 1000 battle deaths per year per participant). I find no statistical relationship between either the index of economic freedom, or the democracy variable, either separately or together, using these data. The effect of capitalism is either more subtle, reducing conflicts only over a lower intensity, or the sample of wars is too small, or both. In any case, democracy does not have the effects Dr. Rummel claims in these data, even when it is left by itself in the regression. As a further check on these findings, I also examined data from the Stockholm International Peace Research Institute (SIPRI). These data report conflicts involving at least 25 fatalities. Thus, they are clearly conflicts involving “violence.” Using SIPRI conflicts as the dependent variable, I am again unable to find a statistically significant relationship linking democracy and peace. I can, on the other hand, find weak support for the suppression of major violence by the economic freedom variable. This variable is just short of the 5% significance threshold in a quick statistical comparison of democracy and capitalism as determinants of peace.

So, to summarize, Dr. Rummel’s critique that I should look at wars seems unfounded, though it did not hurt to check. The claim that democracy generally causes peace is again unsupported.

Dr. Rummel claims I am using the wrong data and that my study “confounds nonviolence with violence.” I am not sure what this means. Every Correlates of War Project MID involves threats or acts of a militarized nature, almost all of which involve violence (the threshold for inclusion in the dataset is high, resulting in relatively few threats and more “uses of force”). Again, I rely on the same data as democratic peace researchers, the most widely used and referenced data, in fact, in the quantitative study of international relations. For Dr. Rummel to claim that the MIDs data are not an appropriate framework for testing the democratic peace is to reject most studies of democratic peace out of hand, something I, and most other researchers, are unwilling to accept.

Still, it would be nice to establish that my findings do not depend on a particular kind of data source. MIDs, COW wars, and the SIPRI data code conflict behavior of a given intensity level or higher. The Interstate Crisis Behavior dataset, on the other hand, examines crises. This can be useful because some conflicts, even relatively violent ones, do not involve direct leadership decisions. Suppose some sergeant decides to lob mortar shells at the enemy, perhaps because he is tired, irritated, or afraid. This would be a MID, and possibly a SIPRI conflict, depending on casualties, but it would not be an ICB crisis if the actions of the sergeant were not initiated by national leaders. The ICB data have also been used in studies that support the democratic peace (Hewitt and Wilkenfeld 1996), and potentially better reflect some of the arguments made about why democracies should be more peaceful. If democracies are more peaceful in any context, it should be in situations where decision making is explicit, conscious, deliberate, and not the result of accidents on the front lines. Results using the ICB dataset, however, are largely the same as those I report for MIDs in my chapter in the 2005 edition of Economic Freedom of the World.

Dr. Rummel argues that collinearity between economic freedom, other variables, and democracy interfere with the effect of democracy on militarized disputes. As Dr. Rummel almost certainly knows, but did not explain to the reader, multicollinearity is not a severe problem in multivariate analysis until correlations are quite high, on the order of 0.9 (he argues they are 0.7. I find that the two key variables correlate at 0.4135). Similarly, the idea that democracy creates capitalism is, I think, questionable. Few, if any, of the archetypal laissez faire economies of nineteenth century Europe would be considered democratic by contemporary standards, though they became democratic in time. Similarly, in South Korea, Singapore, Taiwan, and elsewhere in recent decades, capitalism and development gave rise to pressures to democratize, not the other way around. Rather than treat democracy as a gift of the gods or something that landed from outer space, it seems more reasonable to recognize that democracies formed out of the same soup as did contemporary capitalism and economic development. In any event, the claim that capitalism and democracy are correlated does not obviously lead to the conclusion that democracy should be given preference (or deference) as the key contributor to liberal peace. If the two processes are related, then why treat one as if it is important and the other as if it does not exist?

Yet, again to be safe, I remove all of the variables from the regression model, except democracy. Democracy is not remotely statistically significant, even with no competitors (P value 0.448). Maybe economic freedom gets “help” from the other variables? I ran the regression model with just democracy and the freedom index, and find that economic freedom is statistically significant (P value 0.001), while democracy is insignificant. The claim about sampling is debatable, and is debated, in the literature. Whether we observe all possible states of the world, or just the ones that came to pass in this iteration of history hinges on issues outside the realm of the knowable. Democratic peace researchers have consistently used the statistical significance of democracy as evidence of the validity of their claims. How else can I challenge the conventional wisdom?

At several points, Dr. Rummel notes that “there are NO (zero) wars between democracies over almost two-centuries.” This sounds persuasive, but note that the claim treats as a conclusion that which is presumably the subject of this debate. Is it democracy that makes peace or something closely associated with democracy? Dr. Rummel emphasizes that capitalism is correlated with democracy, but refuses to treat seriously the possibility that it is capitalism that causes peace. The “two-centuries” claim is also misleading. Democratization is a recent phenomenon in world affairs. How many two-centuries old democracies are there? Indeed, we can also say that over the same period, no advanced free market economies have gone to war with each other, either.

Dr. Rummel asks “How could CATO let such a poor study into their prime report?” Clearly, this is a rhetorical question, but let me answer it as honestly as I can. The study conforms as closely as possible to the state of the art in democratic peace research. Rather than being “incompetent,” I adopted the same variables and evaluation standards, and a similar research design to those of the most widely cited research program on the democratic peace. That this happened to be the approach of Oneal and Russett and not Rummel is unfortunately a consequence of the greater popularity of the former among researchers and the wider public. Dr. Rummel does not like the choices I made in my analysis, but he does not like the choices made by other democratic peace researchers either. Differences between Dr. Rummel’s views and those of the larger democratic peace research community were not made clear in his comments, a possible source of confusion.

At the same time, I do not claim that my findings are definitive. They are a cautionary tale that gives some backing to those who are concerned that enthusiasm for the democratic peace has exceeded good judgment. No doubt this is not the end of the debate, though I hope Dr. Rummel and other interlocutors will cease from impugning my professional reputation every time I offer evidence that differs from their conclusions. Science is a perpetual learning process, in which we gradually whittle away at uncertainty. The fervor with which researchers on the subject hold to their respective visions of democratic peace should itself lead intelligent observers to caution.

Let me add in closing that, while the study Dr. Rummel critiques does not directly contradict the dyadic version of the democratic peace, my other research does. I have replicated the major dyadic studies of Oneal and Russett and others, using several indicators of capitalism, including but not limited to, the Index of Economic Freedom. I find that democracy does not sustain a dyadic effect on conflict either (there is not even a special peace among democracies), when appropriate measures of global market integration and economic development are introduced. I have shared these findings with democratic peace researchers (John Oneal, Bruce Russett, Erik Weede, Patrick James, James Lee Ray, to name a few), and expect that they will soon be available in print. Of course, I will also provide copies to Dr. Rummel, if he wishes.

posted by Dan on 09.15.05 at 10:34 PM


Erik still isn't responding to the more serious problem, which is the timeframe of his data set. Of course, Rummel didn't comment on that...

posted by: Dan Nexon on 09.15.05 at 10:34 PM [permalink]

Dan Drezner generously posted my reply to Rummel. I noticed Dan Nexon's comment.

Yes, I am not thrilled about the short timeframe. I have looked at other indicators, including several coded from IMF data, and FDI and Portfolio investments that go back a bit further. Obviously, for the chapter in the Economic Freedom of the World report, I needed to use the Index of Economic Freedom, but I find pretty much the same thing using other indicators of capitalism. The problem is that we just don't have (or I don't have -- if someone does please tell me) good data on financial openness going back prior to the 1960's.

I would add that this is the period during which democracy proliferates (there are relatively few democracies prior to de-colonization in the late 1950's) and democratic peace is said to be most robust. If anything, the sample really benefits the democracy variable. Similarly, missing observations for the capitalist variables reduce the variance (read "explanatory power") in these variables. States that will not, or cannot, disseminate statistics to sources such as the IMF tend not to have open economies. For this reason, democratic peace scholars often replace missing values in trade data, for example, with zero's. I did not do this for fear of creating additional controversy.

posted by: Erik Gartzke on 09.15.05 at 10:34 PM [permalink]

Hi Erik and Dan,

My main quibble with much of this discussion is that everyone seems to assume a simple relationship between pacifism and peace: If a certain type of state is more pacific, it will get involved in fewer wars; conversely, if a certain type of state gets involved in fewer conflicts, it must be more pacific.

But we know that the relationship between pacifism (the preference) and peace (the outcome) is not necessarily that simple. A type of state that is known to be averse to war might find itself in just as many wars as a more aggressive state simply because it is picked on more often. Similarly, war-like does not necessarily imply war-prone. A type of state that is known to be belligerent may rarely actually have to fight, if others fear it sufficiently.

Hence, we need to be careful in inferring too much about a state's pacifism or belligerence simply from its observed frequency of engaging in conflict.

posted by: Ken Schultz on 09.15.05 at 10:34 PM [permalink]

Very interesting points from both of you.

I can't help but think of the latter stages of the Dutch Revolt, when both sides found it necessary, IIRC, to continue trading with one another in order to support their mutual hostilities. Of course, Spain would score pretty darn low on the "economic freedom" scale....

posted by: Daniel Nexon on 09.15.05 at 10:34 PM [permalink]


good, polite and elaborate response. Thanks.

posted by: Nick Kaufman on 09.15.05 at 10:34 PM [permalink]

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