Historically, how does private policing compare to public policing? Gene Callahan answers this question by looking at a homicide rate time series for England, pointing out that roughly 800 years ago the crime rate was roughly “20 times today’s rate.” He notes that the decline in the homicide rate coincides with a continuous growth of the state. He admits that correlation is not causation, but he thinks it’s fairly clear that the correlation is not mere coincidence. I sympathize with the argument, but it suffers from an omitted variable bias, and in fact the number of omitted variables is probably very large. Further, what did directly cause the decline in crime could be things that would coincide with both public or private security. But, in the end, I say all of this as someone who believes that public security has provided society a net benefit.

I’m of the opinion that private security makes sense in a world where the distribution of force is relatively equitably distributed, such that the costs of violence are, on average, too high. This means that private security hasn’t been viable for most of human history, and it’s not obvious that it’s possible today. This implies that the state, so far, has most likely been the most efficient means of maintaining peace. While its present viability is not obvious, I do think the case for the superiority of private security is pretty high, but only by making one very likely erroneous assumption. I think the kind of justice and the means its enforced by would be very different from present day. An immediate change, I think, would cause a cultural shock. If we do away with the assumption that people will deal with this shock, then private security can’t work until institutions — including culture — develop to that point. This implies a transition over a large number of years.

But, it’s not difficult to see how Gene’s comment is not convincing to the anarchist. Consider the following possible causes of the long-term decline in homicides,

1. Better communication technology, allowing more crime to be reported to the authorities;
2. Faster means of transportation, allowing the authorities to more quickly respond to reported crimes;
3. Better, more expensive weaponry, giving authorities an advantage with economies of scale — individual criminals may not be able to afford them;
4. Growing economic wealth gradually increased the opportunity cost of crime, shifting the supply of crime to the left;
5. Better non-violent home protection systems, including homes that are more difficult to break into, home alarms, et cetera;
6. Criminals typically have non-random backgrounds, meaning that improvements in wealth also reduce the size of environments which are more likely to induce criminality;
7. Changes in weapon technologies make it easier for non-skilled users to fire more lethal weapons, making it easier to stop assailants (raising the cost of crime);
8. Various things that are extremely counter-intuitive that we may not recognize. I have in mind, as an example, Donohue’s and Levitt’s work on the relationship between abortion and falling crime rates. I understand that there are convincing arguments that show a number of problems with their methodology. But, my point is that there are things that are extremely non-obvious, and in fact until someone is creative enough to come up with a novel causal relationship we may even be convinced that there is no causal relationship whatsoever.

I can think of a lot of other plausible explanations for declining homicide rates in England. But, if you assume that private security is possible, none of these things are factors which are preferable to state security, but not to private security. That is, if we strictly model the security industries, the list is entirely composed of variables exogenous to the model. They are all changes with positive externalities, which affected the provision of security. If we assume private security was possible in 1200, then the time series may show exactly the same relationship. In fact, if private security is really more efficient than public security, then we’d see a superior trend.

There are a lot of anarchists that strongly believe private security is possible. If a lot of the reasons for a decline in crime are unrelated to actual institutions of justice, then it’s not difficult to see that the use of the trend line to argue in favor of public security is not convincing. I suspect that the issue that many anarchists have with Steve Pinker’s The Better Angels of our Nature. (In Pinker’s case, though, I think most are underestimating the book.) But, it’s not obvious that all increases in world peace have been caused by the state itself, rather than concurrent cultural, economic, institutional changes which bestowed upon society the benefit of greater peace. Maybe increases in the cost of weaponry, especially when we consider military-grade weaponry, induced economies of scale, by increasing the initial cost of warfare (weaponry, military training, deployment, et cetera). This forced governments to wage larger wars, but at much fewer intervals, and at higher costs (in price and, especially, in human life). These are all externalities that private institutions of justice would also benefit from, if they were possible.

It’s also worth considering that most modern-day anarchists don’t care about what was possible 800 years ago. They care more about what kind of institutions are possible today, or even in the near future. And, so, while there is a high probability that the state was absolutely necessary for most of human history, it doesn’t take away from the likelihood that none of the major factors that reduced the crime rate would cease to exist in a world of private justice. That being said, there are also many anarchists who believe that the state was never necessary. These people are even more likely to dismiss Gene’s argument, and even a weak version of Pinker’s. Although, to these people I’d show the differences in income growth rates between historical stateless, or relatively stateless, societies and societies with centralized governments. The latter, without a doubt, has, to date, shown the most possible results. In any case, what I’m trying to say with respect to Gene, is that it’s not clear that the evidence is so evidently in favor of public security.

On a tangentially related note, the case for the state became clearer to me in a short conversation with a professor on Daron Acemoglu’s and James Robinson’s Why Nations Fail. I mentioned my disagreements with the authors’ assumptions on the benefits of centralized states. He asked me if I knew what they had in mind when they made the claim, and in that exact moment I realized that the benefit they have in mind is that as the number of governments decrease, the probability of inter-state warfare falls. This also means that there are less governments to fight over extractive institutions, which may otherwise suffer from even stronger temporal rigidities. Maybe this already seems obvious to you, but I think the point was poorly articulated in the book. The authors, for example, cite tax increases as evidence of stronger, more inclusive political institutions. And, they fail to acknowledge that Somalia, during its years as an economically growing, virtually stateless society, actually did relatively well (in pace of improvement). They make other assumptions, as well. At one point they make the claim, at least in my interpretation, that relatively centralized governments are necessary prerequisites for vibrant urban trade centers. The claim was made with regards to early cities. But, maybe other factors — such as factor endowments, geographical location, et cetera — invited greater merchant activity, which in turn made extractive institutions like state bureaucracy possible. The way they present the case for centralized governments is not as strong as it could be.

But, look at the case for centralized governments this way. When there are many small geographical jurisdictions, with the assumption that the market is till too uncompetitive to fully discourage war and conquest through private security, the probability of war grows. As governments come to control larger quantities of land, forcing many governments to cease existing, there is a lower probability of border conflict, and war in general. In this sense, the centralized state can be seen as a net benefit. I feel that this is actually what Acemoglu and Robinson actually have in mind. I think it’s a strong argument.

Coming back to the main point on omitted variables, it’s not at all obvious that the decline in England’s homicide rate is directly attributable to the provision of public security. In all actuality, it’s more likely that the market for security benefited from a long list of positive externalities, mostly associated with economic and technologies improvements. But, there are strong arguments for the existence of the state, such as institutional concerns, that would enrich the debate if they were more regularly addressed.