No peace in our time?

Pinker's response is shall we say interesting, first he says:

The book does not claim that the mean of the distribution of war deaths has changed; it explicitly notes that power-law distributions (such as those commonly fitted to war deaths) don’t have calculable means. Like Taleb, the book points out that empirically observed data from the tail of a power-law distribution provide unreliable evidence for its underlying parameters.

He than proceeds to demonstrate that he doesn't in fact understand the implications of these statistics by writing stuff like this:

Finally, Taleb thinks that it is damning that “You can look at the data he presents and actually see a rise in war effects, comparing pre-1914 to post 1914.” Yes, that’s exactly what I point out: great-power wars became steadily more destructive from 1500 through 1945. The turning point that marks the onset the Long Peace was in 1945, not 1914.

A power law distribution means that at any given time not during a major war it looks like war has fallen to unprecedented levels.

A hypothetical proto-Pinker writing in 1913 could similarly note that the turning point was in 1814, possibly even citing the Franco-Prussian war to show how wars between great powers are now short and limited.

Note that that looks like Steven Pinker's 2012 response to Taleb's earlier criticism of the book. I don't think it's a newly written response to Cirillo & Taleb's paper.

5.4 million is the upper estimate - and my "5-10 million since WW2" is really "10 million per world population in 2015 of 7.2 billion", which is 10 million (6.7/7.2) = 9.3 million in 2008 and 10 million (5.97/7.2) = 8 million in 1998; both are above 5.4 million.

It's not stated in the paper what they mean by "victims", but they count 70 million or so victims of WW2, which has a death toll ranging from 50-80 million, so it seems that "victim" means "dead".

Could happen.

Indeed. This is not a proof of the "long peace", just showing the paper doesn't disprove it.

Ooops, sorry - because I copy-pasted it from the article and didn't remove the cross.

Your link seems to argue that peace interventions aren't maximally efficient, not that they're not useful. As for why peace is a good metric to use, war (for the majority of the population affected) is a sufficiently clear negative that it would take extremely strong arguments to show peace is not an important positive good. Just look at the revealed preferences of refugee flows, if nothing else.

Pinker argues that all types of violence are going down. Cirillo and Taleb deliberately chose to ignore homicides:

We avoided discussions of homicide since we limited L to values > 10, 000, but its rate doesn’t appear to have a particular bearing on the tails. It could be a drop in the bucket. It obeys different dynamics. We may have observed lower rate of homicide in societies but most deaths risks come from violent conflict.

I'd note that they chose to ignore homicides, and it seems that homicides undermine their general point.

Even at high homicide rates (e.g. Russia) it would take many many years to add up to even a small war's casualties.

Or how about the threat of violence to keep people under control?

That paper provides an alternate explanation for the long peace thesis.

However, it rejects "per capita deaths" as a good measure of rate of conflict, which makes it pretty dubious (people are fully aware that per capita is ideal for comparing homicide rates; why suddenly reject it for war deaths?) They write nonsense like:

Moreover, population growth is exponential [...] We should hardly be surprised that deaths from war cannot keep up.

More people means more soldiers, larger economies (hence more manufacturing of weapons), more and larger groups with reasons to rebel/fight/steal each other's stuff.

They do have an interesting point with "war as information gathering/negotiations". But a lot of the rest seems to be a conflation of "the reasons things are getting more peaceful are not nice reasons" with "things are not genuinely getting more peaceful".

"The proliferation of states in the 20th century" was not an exogenous event, but explicit decisions made by the victors of WWI and WWII, specifically to prevent violence, so they should get credit for them.

Pinker tries to provide several complementary explanations for his thesis, including game-theoretic ones (asymmetric growth, comparative advantages and overall economic interdependence) which could be considered "not really nice reasons for measuring our (lack of) willingness to destroy each other". Like SA said, Braumoeller seems to conflate 'not very nice reasons to maintain cooperation' with 'our willingness to engage in war hasn't changed'. And this is one of the reasons why Taleb et al. missed the point on Pinker's thesis. To test if it's business as usual, if our willingness, what ever that is isomorphic to, is the same, one needs to verify if State actors are more likely to adopt the risk dominant equilibrium than the payoff equilibrium or if there is intransitivity. There is a connection between the benefits of cooperation and the players willingness to coordinate. What if the inability to dominate places our future in a context where we see don't see fat tails in deaths from deadly conflicts? What if the benefits of cooperation increases over time along with the the willingness to coordinate? What if it's not business as usual?