Consequentialism for beginners

by John Quiggin on December 7, 2004

Now that, thanks to Kieran and the Medium Lobster, we’ve all had our fun with Richard Posner’s case for pre-emptive war, complete with toy numerical example, it’s time for me to play straight man.

Posner’s starting assumption is consequentialism: that we should evaluate an action based on whether its probable consequences are, on balance, good or bad. I broadly agree with this, so I’ll try to explain why it shouldn’t lead to conclusions like those derived by Posner.

I’ll ignore a range of more complex objections and come straight to the first distinction learned by beginning students of the subject. Should we evaluate the consequences of general rules such as “don’t engage in pre-emptive wars” (rule-consequentialism) or should we evaluate each action on a case by case basis (act-consequentialism)

For perfectly rational decision makers, following the rules of Bayesian decision theory, the answer is easy and, in fact, trivial. It’s best to make the optimal decision on a case by case basis, and an optimal set of rules would be so detailed and precise as to yield the optimal decision in every case. Posner routinely assumes this kind of perfect rationality, which is why he doesn’t see any big problems with toy examples, or with claiming that this kind of reasoning can usefully be applied to improbable catastrophes with incalculable consequences.

There are two objections that can be made here

  • Human beings are not perfectly rational and do not follow the rules of Bayesian decision theory
  • Since war is a negative sum game, rational decision makers do not fight wars[1]

The first point is well known, and has been demonstrated by the work of economists like Allais, and psychologists like Kahneman and Tversky (yes, we’ve got Nobel prizes on our side of the argument as well!).

But it’s the second point that’s really critical. Posner’s one-sided discussion of pre-emptive war, with no consideration of the opponent’s motives, is broadly equivalent to the Medium Lobster’s assumption that the other side of the proposed war consists of malign Moonmen (Anglais Casse has more on this). In this respect, and in his failure to consider the possibility that the pre-emptive war might end in defeat, Posner illustrates two characteristic biases of human beings on this subject.

  • we tend to overestimate the malignity and underestimate the rationality of people different from ourselves[2]
  • we tend to overestimate our own competence, and ignore the likelihood that our plans will fail

So, in relation to war, the case for adhering to rules that would discourage resort to war, even when a Posnerian calculation suggests that it looks like a good idea, is particularly strong.

In particular, experience suggests that the case against pre-emptive war is remarkably strong. Lots of pre-emptive wars have been planned, and many commenced. In many cases where pre-emptive war was suggested but not undertaken, the danger has resolved itself peacefully. In many cases where a pre-emptive strike has been planned, the intended quick knockout has turned into a long grinding war, often ending in defeat.

The example almost invariably cited here by supporters of pre-emptive war, and chosen by Posner, is that of Hitler. Posner suggests that a pre-emptive war to overthrow Hitler would have been an appropriate response to the reoccupation of the Rhineland. For the reasons put forward by many of the commenters on Posner’s blog, I don’t think this is clear even with the benefit of hindsight, and it certainly couldn’t have been justified on the basis of what was known about Hitler in 1936. An invasion of Germany, based on a violation of a treaty regarded by all Germans and many others as grossly unfair, would have been a highly dangerous undertaking and could easily have failed. Much the same would be true of an invasion in response to the annexation of Austria.

Certainly, the British and French governments should have learned more than they did from these events, and should have taken a stand at Munich. But the resulting war would have been one of collective self-defence like the actual one, though with a better starting point.

fn1. Minus the game theory, this point was made by Geoffrey Blainey in “The Causes of War” , and I got it from him.

fn2. Of course, Al Qaeda and similar terrorist groups are indeed both irrational and malign. But such groups rarely control the kind of state against which a pre-emptive war can be undertaken. Afghanistan was an instance, but a rare one.

{ 53 comments }

1

Kieran Healy 12.07.04 at 11:59 pm

Well I wasn’t just taking the piss with my two posts: I wanted to raise some questions about the kinds of problems Posner’s cost-benefit approach could reasonably be applied to, just as you raise questions about the kinds of agents required to reasonably apply it.

2

ogmb 12.08.04 at 12:17 am

The “other side” in the game is not Saddam (a pawn), but the Democratic opposition (and in extension, “Old Europe”). The game is called Reelection, and since GWB doesn’t foot the bill or carry the human toll of the war, he won.

3

Carl von Clausewitz 12.08.04 at 12:22 am

Although our intellect always longs for clarity and certainty, our nature often finds uncertainty fascinating.

4

Kurt 12.08.04 at 12:31 am

“..an optimal set of rules would be so detailed and precise as to yield the optimal decision in every case.”

suggests the problem that Godel spotted.

5

John 12.08.04 at 12:32 am

An invasion of Germany, based on a violation of a treaty regarded by all Germans and many others as grossly unfair,

It is widely forgotten, but the reoccupation of the Rhineland not only violated Versailles, which fits this description pretty well, but also the Treaty of Locarno of 1925, which Germany had entered into willingly. Nevertheless, I would most strongly agree with the basic premise that an intervention in 1936 would have been a bad idea.

6

Matt Powell 12.08.04 at 12:50 am

Although I agree that Posner’s analysis is not very helpful, I disagree w/ your criticism here. The fact that the relevant political actors will not be following bayesian theory does not prevent us from using it to consider the wisdom of starting a particular war. Further, the fact that political actors are, in fact, irrational makes your second point less relevant.

7

mpowell 12.08.04 at 12:52 am

Although I agree that Posner’s analysis is not very helpful, I disagree w/ your criticism here. The fact that the relevant political actors will not be following bayesian theory does not prevent us from using it to consider the wisdom of starting a particular war. Further, the fact that political actors are, in fact, irrational makes your second point less relevant.

8

Walt Pohl 12.08.04 at 12:59 am

I think that one of the functions (perhaps even _the_ function) of rule-based morality is that it gives us guidance when we can’t do the cost-benefit analysis, which is most of the time.

9

Giles 12.08.04 at 1:02 am

“In particular, experience suggests that the case against pre-emptive war is remarkably strong.”

That experience is mainly present in countries that have won defensive wars; countries that have suffered heavily in defensive wars probably dont feel the same. Russia and Iran come to mind; Russia was understandably very in favor of pre-emptive action after WW2, and alot of the offensive attitude of the Iranian goverment probably stems from the Iran-Iraq war. By contrast, some nations drop out of the baysian process by not pre empting – I expect that say the Plains Indians think they should have pre empted the settlers in 1600.

I’m therefore not convinced that a baysian analysis delivers a unique or meaningful answer.

10

ChrisPer 12.08.04 at 1:05 am

I confess to being a beginner, so the headline indicates you are writing for me.

If the starting point is that we evaluate an action based on its consequences, whether on an act or rule basis, that excludes taking action knowing the consequences are deleterious, just because you choose to act in accord with principle.

For instance, the peace activists hypothetically flocking to Iraq to act as human shields for police stations are acting out of principle; even though they personally will suffer costs in the action up to and including death, their principles offer a rationale of potential good if others adopted their ethic, or are merely deterred from murder by their presence.

Similarly each of us with a neighbor suffering domestic violence has the choice; knowing WE can act but will get no thanks – just the risk of murder, the possibility of assault and the certainty of abuse by either or both parties. This consequentialism is the root of the ‘not my business’ response to domestic violence.

11

Jim Miller 12.08.04 at 1:09 am

Interesting. An economist who doesn’t believe in evolution — apparently. I hope Professor Quiggin will explain that.

12

Will Ambrosini 12.08.04 at 1:43 am

I hope you’ll elaborate on the second point about war being a negative sum game. Intuitively, this seems wrong. I would think it easy to construct an example, from history or otherwise, of a war with positive gains in sum. Off the cuff, imagine a war were the attacked lay down their arms without a shot fired. The victors march in, institute democracy, grow the economy and are adored by the conquered. Wouldn’t this ‘war’ be positive sum?

Also, your arguments on this point seem to just have the effect of increasing the costs as discussed in Posner’s post. You’ve discovered some ‘hidden costs’ in the Posnerian calculation. That’s fine. Realize those costs and then redo the calculation.

13

Potemkin Cruise 12.08.04 at 2:18 am

Ah, finally a thread for us rank novices (not being a decision theory expert, Im not being sarcastic here either). I enjoyed the humor in the prior posts to a point, but was vaguely uncomfortable with the relatively light engagement with the substantive faults of Posner’s analysis. Moving on to those…

Got the point about improbable catastrophes, etc. Seems to be a deal killer for any deterministic rules justifying pre-emptive war in the abstract. Also got the point regarding the limited rationality of the actors and the high likelihood that they will simply be wrong.

From this, though, it does not seem to follow that the consequences and probabilities of war are always so unknowable under every factual situation such that 1) cost-benefit analysis, even under bounded rationality, is always useless, and 2) that pre-emptive aggression can never be justified under such an analysis.

Now, I know there is more to the analysis than what I’ve just set out. But what? Does it just boil down to your faith in human (ir)rationality?

14

BigMacAttack 12.08.04 at 2:47 am

Walt Pohl,

You said, what I think, better than I could. Thanks.

Our deontological rules should be based on utilitarian outcomes over long periods of time, and should be adhered to, unless, at a minimum, the utilitarian case is very strong.

But will that still work in our rapidly changing world?

Now, you say it better.

15

derrida derider 12.08.04 at 2:54 am

Will, that’s silly. Of course we can construct an imaginary example of a ‘win-win’ war; it’s just that the preconditions very rarely obtain in reality. The neocons are rightly considered fools for kidding themselves that Iraq was an exception.

If the past teaches us anything, it is that war tends towards ‘lose-lose’ with occasional ‘win-lose’. The likelihood of ‘lose-lose’ has to enter our prior calculations. And as others point out calculations geared to ‘win-lose’ ignore the welfare losses of the losers.

16

derrida derider 12.08.04 at 2:55 am

Will, that’s silly. Of course we can construct an imaginary example of a ‘win-win’ war; it’s just that the preconditions very rarely obtain in reality. The neocons are rightly considered fools for kidding themselves that Iraq was an exception.

If the past teaches us anything, it is that war tends towards ‘lose-lose’ with occasional ‘win-lose’. The likelihood of ‘lose-lose’ has to enter our prior calculations. And as others point out calculations geared to ‘win-lose’ ignore the welfare losses of the losers.

17

John Quiggin 12.08.04 at 3:07 am

Kieran, I thought both you and the Lobster made more serious points than the Judge and Becker combined. But they were still excellent piss-takes.

18

fasteddie 12.08.04 at 3:14 am

Since war is a negative sum game, rational decision makers do not fight wars

Brilliant. Even Desert Storm or Afghanistan (which wer as “positive” as any wars could have been) were undoubtedly lose-lose.

Precision strikes and in & out guerilla actions (SEAL / Special Forces ) may be zero-sum or better, but they do not like constititue “war”.

19

PanJack 12.08.04 at 3:53 am

Perhaps I’ve missed something important.

But Posner certainly needs to differentiate between “rational”, on the one had, and “good,” “moral,” or “just” on the other.

This distinction is clear within classic utilitarian thinking, but has seemingly dropped by the wayside in modern faux-thinkers like Posner.

Act A (or rule A) might be “rational” for Person X in the sense that it maximizes whatever they are maximizing. But this does not mean that A is “rational” or “good” from the point of view of society: X plus those who are not X. In this case, those who are not X include those who are attacked preemptively.

Of course, we can define those we attack as non-persons who don’t count. Or was this assumption made?

20

Walt Pohl 12.08.04 at 3:54 am

Bigmacattack: Thanks!

21

PanJack 12.08.04 at 3:54 am

Perhaps I’ve missed something important.

But Posner certainly needs to differentiate between “rational”, on the one had, and “good,” “moral,” or “just” on the other.

This distinction is clear within classic utilitarian thinking, but has seemingly dropped by the wayside in modern faux-thinkers like Posner.

Act A (or rule A) might be “rational” for Person X in the sense that it maximizes whatever they are maximizing. But this does not mean that A is “rational” or “good” from the point of view of society: X plus those who are not X. In this case, those who are not X include those who are attacked preemptively.

Of course, we can define those we attack as non-persons who don’t count. Or was this assumption made?

22

PanJack 12.08.04 at 3:55 am

Perhaps I’ve missed something important.

But Posner certainly needs to differentiate between “rational”, on the one had, and “good,” “moral,” or “just” on the other.

This distinction is clear within classic utilitarian thinking, but has seemingly dropped by the wayside in modern faux-thinkers like Posner.

Act A (or rule A) might be “rational” for Person X in the sense that it maximizes whatever they are maximizing. But this does not mean that A is “rational” or “good” from the point of view of society: X plus those who are not X. In this case, those who are not X include those who are attacked preemptively.

Of course, we can define those we attack as non-persons who don’t count. Or was this assumption made?

23

Thomas 12.08.04 at 4:54 am

What an odd argument. Suppose that Posner is correct, that there are circumstances in which it is rational to choose preventive war, and that we as a nation are faced with such circumstances. Suppose further (I know, this is sounding like Posner, but bear wth) that we had adopted John Q’s heuristic, which guides us to reject preventive war. John Q apparently would consider that outcome a success for his heuristic. Which is odd, because such circumstances (circumstances where the rule doesn’t give the right (maximizing) result) are typically thought to be the argument against rule-utilitarians, not the argument for. But maybe that objection doesn’t matter in consequentialism for beginners, only in the more advanced coursework.

Based on the lack of a sputtering response from Kieran, I guess we can assume that this rather brief discussion of Hitler and preventive war counts as “satisfactory.” I’ll leave that to others to understand–I confess that it is way beyond my meager abilities.

24

ogmb 12.08.04 at 6:47 am

“Since war is a negative sum game, rational decision makers do not fight wars”

I don’t know what kind of game “War” is, but if you’re thinking of a repeated prisoner’s dilemma with war/war the Nash equilibrium of the one-shot subgame this has nothing to do with negative sum, and war/war is a Nash equilibium strategy for rational actors: Under the expectation that the other side wages war, war is the rationally optimal response for both sides.

You’re probably thinking of a game with endowments. If both sides start off with endowments E1, E2 and playing peace/peace increases the endowment each round while war/war (and peace/war for the dovish side aka sucker) reduces it, starting a war is not a rational strategy for the side with lower endowment (assuming a payoff between sucker and penalty in eternity after the war is lost), but might be for the party with higher endowment (although it might be dominated by extortion). Of course all of this only holds if the cost of war is known a priori. If the comparative cost of war, and in extension time until victory/defeat, has to be established by Bayesian updating war might very well be a rational strategy for the lowly side, depending on the priors. It requires overconfidence though, i.e. war must be more costly or lengthy (or the spoils of victory less profitable) than anticipated at least for one side, if not both. This might be what you were trying to get at.

25

antman 12.08.04 at 7:53 am

This discussion is centering on the decision to wage war or not, but wasn’t the question (or one of the questions) in the leadup to the latest Iraq war whether it was better to go to war or to continue sanctions and inspections? Both are preemptive but with obviously quite different costs and benefits, the sanctions having as part of their costs the still non-zero, but now much lower, probability of an attack. How does one go about choosing amongst different kinds of preemptive actions (and lets not forget the bribe diplomacy being pursued in NK and Iran).

26

dsquared 12.08.04 at 7:57 am

OGMB, since wars by definition involve the diversion of productive resources into producing expensive pieces of capital equipment which are delivered to people who don’t want them and then explode, they can’t be positive or zero-sum events. Any war is Pareto dominated by a contract under which both parties agree to the outcome that the war would have produced without fighting.

I’d add a third bullet to John’s points in favour of rule-utilitarianism above:

* There is no basis for assuming that the probabilities one would need in order to be a fully rational Bayesian decision maker actually exist, let alone that there is a sensible basis for constructing an assumed prior and likelihood function.

27

Eve Garrard 12.08.04 at 9:42 am

John, you say that a characteristic bias of human beings is that we tend to overestimate our own competence, and ignore the likelihood that our plans will fail. I’m sure you’re correct about this. But surely it’s going to apply to any human decision-making, not just to the decision to go to war? So it will apply just as much to the decision not to go to war. The spectacle of UN, and indeed worldwide, inaction in Darfur is one such case; see also Rwanda, and the use of sanctions against Saddam’s Iraq. Unless we are *already* committed to pacifism, I don’t see why this feature of human decision-making tells particularly against military interventions.

28

Chris Bertram 12.08.04 at 10:44 am

As I said in an earlier thread, I’m sceptical about giving consequentialism the role that John wants it to play in thinking about war and peace.

We ought to distinguish, though, between two roles for consequentialism: (1) we use consequentialism as a decision-making tool, either directly in the evaluation of acts or via rules; and (2) we use consequentialism as the explanation for the system of prohibitions, permissions and so-on that we employ.

I don’t want to rule out the thought that (2) might provide the best explanation for our norms (though I doubt it). What I do think important, though, is that whether or not we think that the underlying explanation/justification is provided by consequentialism or by something like a casuistic reflection on the justification for individual self-defence (etc.), we have good reason to settle on a system of norms to govern war and peace, norms that are common knowledge among the participants, can predictably guide their actions (and reactions) and so on …

Two reasons for being skeptical about giving consequentialism the role that John wants it to play in the actual decision-making process, (1) we’re unlikely to achieve a consensus on what the relevant consequences ought to be and (2), for Chou-en-lai like reasons, we can’t calculate them.

To illustrate: WW2, and specifically the decision of the UK and France to declare a state of war in September 1939. With respect to the calculability issue, we don’t know the consequences even now! (And given the way consequences ramify, we never will). On a narrow and crude utilitarian calculation (a Benthamite one if you like) my money would be on the decision to go to war being _unjustified_ . The victims of Nazi terror are so vastly outnumbered by the other dead and maimed, that there is, at least, a real possibility that a narrow u calculus comes out against war.

I think there’s something obviously wrong with this conclusion, though. What’s wrong is that the narrow u calculus is _too_ narrow: we ought to count other things, such as great injustice, in a reasonable calculation of consequences. But I doubt that we’ll achieve consensus on what are the relevant values to build into a wider consequentialist scheme and, depending on how expansionist/inclusivist we are, our justification is going to start looking a lot less … consequentialist.

I do think, though, that a broad consequentialist approach can usefully _supplement_ and inform deliberation within the framework of a set of public norms. Take, for example, the case of the Iraq War. Like the liberal hawks, I believe that the norms, rules and permissions governing just war ought to include at least a permission to intervene to remove a regime that grossly and systematically violates human rights. But unlike them, I think that — especially given the unpredicability of war — we need to be pretty sure that the outcome of our action will be better in broad consequentialist terms (i.e with values like justice built into the calculus) than inaction, or action at some other time. So whilst I think that it would sometimes be justifiable to wage war against a Saddam-like regime, I think this actual war is too uncertain in its (broad) consequences to be justified.

[Short addendum: As I noted in a comment on Kieran’s Posner thread, any conseqentialist calculation ought to be with respect to the costs and benefits from an impartial pov, and _not_ the c&bs to the nation initiating the decision.]

29

david gress 12.08.04 at 11:31 am

Good thread. A couple of random points from a historian who has had a long (25-year) friendly running fight with rational choice types.

As a pragmatist and nominalist, I don’t know how far you can get with armchair or blackboard speculation about Bayesian rationality and game theory. I hold to Geoffrey Blainey’s wonderfully faux-simple definition, that wars happen because the differing sides don’t agree about their relative strength. When they agree, the weaker side gives in, and the war doesn’t occur. (The exception is when the weaker side knows it’s weaker, but fights to preserve honor, as in the case of Norway against Germany in April 1940). Blainey’s explanation wisely prescinds from what we usually call the causes of wars, because they are always political and not meaningfully subject to Bayesian or any other rationality calculus — or so I say to my rational choice friends.

Smaller point: Plains Indians”, “pre empt the settlers”, and “1600”?? Apart from the ahistorical and moralizing underlying assumption (white settlement of N. America was immoral), the phrase is weird. Plains Indians were thousands of miles from the Massachusetts Bay Colony and hardly encountered white settlers before the mid-19th century. A coalition of upriver Hudson Tribes did try to eradicate the settlers in King Phillip’s War (1675-76), a very bloody affray indeed.

30

abb1 12.08.04 at 11:44 am

It’s the radical nature of war that presents difficulty here, because this ‘consequentialist’ approach seems perfectly reasonable when appied to a more banal situation, like a tax policy or something.

It’s just that human behavior in extreme situations is pretty much unpredictable. If you ask me: say, a guy is threatening you with a knife, what do you do – run away? attack him? break down in tears? Well, the answer is: I have no idea what I would do. C/b analysis doesn’t work here.

So, if we accept that the actors in this particular situation probably won’t act rationally, this throws the whole premise out of the window; nothing much to analyze here.

31

dsquared 12.08.04 at 12:06 pm

Unless we are already committed to pacifism, I don’t see why this feature of human decision-making tells particularly against military interventions.

Because, on a strict relative historical frequency basis, wars have in general made things worse rather than better. Also, as I pointed out above, wars cost money (money which is spent making things which are typically delivered to people who don’t want them), so there has to be a presumption ceteris paribus against doing so.

32

Eve Garrard 12.08.04 at 12:29 pm

Dsquared, I agree with much of what you say, especially the ceteris paribus presumption, but that doesn’t settle the problem that bothers all non-pacifists, namely *which* wars are to be supported. War isn’t the only thing that costs huge numbers of lives (see Rwanda and Cambodia); this is why I think it’s important that John’s point about human bias is going to apply to military inaction as well as to action. And if your key points are the numbers dead and the waste of resources involved in delivering ordnance to people who don’t want it, then your strictures should apply as much to resistance to either internal or external aggression as to the aggression itself. Do you think we have the same kind of reason to avoid defensive wars, or revolution against tyranny, as you’re arguing we have to avoid war simpliciter?

33

Andrew BOucher 12.08.04 at 12:38 pm

“Any war is Pareto dominated by a contract under which both parties agree to the outcome that the war would have produced without fighting.”

Pareto domination is too strong a conclusion. It would then be the case that any (rational) country which knew it would lose, would not fight. As dg pointed out, there are cases when wars are still fought by a side knowing it will lose, because of honor (or other reasons). It is still rational to fight, because the mere fact of fighting is a positive for national pride, which would not have been achieved by supposing the winning side to have got what it wanted without a fight.

34

Dan Hardie 12.08.04 at 1:17 pm

JQ: ‘Since war is a negative sum game, rational decision makers do not fight wars’.

That being the case, are all states which spend money on armed forces led by irrational decision makers?

If not, why not?

If their rationality stems from the fact that they are spending money on armed forces for deterrent purposes with no intention of actually using them in war, doesn’t that rational intention destroy the deterrent effect?

35

Dan Hardie 12.08.04 at 1:22 pm

I think perhaps for reasons of time and politeness I won’t yet venture any comments on your opinions on opportunities to resist Hitler, 1933-9. To be honest, you’ve referred to this fascinating subject more than once, and I think rather than hijack the thread by discussing this topic in the detail it deserves, maybe you could, at some later date, write a post on your view of what Hitler did in the ’30s and when, how and with what chance of success he could have been resisted- and what your sources are for the statements you make. Whilst your knowledge of 1930s Europe cannot be as appalling as my knowledge, or rather ignorance, of rank utility theory, I do suspect it could be improved somewhat.

36

Dan Hardie 12.08.04 at 1:40 pm

Btw, I thorougly recommend Alan Bennet’s play ‘The History Boys’ for those who can make it to the National Theatre in London. The saddest character is named ‘Posner’, although I have no idea whether this is deliberate.

37

dsquared 12.08.04 at 2:01 pm

I think John is entirely correct in his assessment that pre-emptive wars have a much worse record than other kinds of wars.

38

Sebastian Holsclaw 12.08.04 at 5:21 pm

“Brilliant. Even Desert Storm or Afghanistan (which wer as “positive” as any wars could have been) were undoubtedly lose-lose.”

Afghanistan is lose-lose only if you cling tightly to the idea that the invasion had nothing to do with 9-11, and if you believe that letting the organization which commited that war crime run the Taliban would not have led to further atrocities against Americans.

Are you assuming that 9-11 was a rational act to be analyzed under this structure? Was the 9-11 attack a win for Al Qaeda?

I also have to agree with eve that you can’t ignore the costs of inaction in your calculus–a cost almost always ignored by those who argue along pacifist lines.

39

abb1 12.08.04 at 5:43 pm

Afghanistan is lose-lose only if you cling tightly to the idea that the invasion had nothing to do with 9-11, and if you believe that letting the organization which commited that war crime run the Taliban would not have led to further atrocities against Americans.

Bin Laden’s organization didn’t run the Taliban. This is about as accurate as claiming that Likud runs the US government.

40

Walt Pohl 12.08.04 at 6:21 pm

Before we go completely off-track here: neither Afghanistan nor Gulf War I were preventative wars.

41

roger 12.08.04 at 7:27 pm

There seems to be an odd current in this discussion of war, in which wars are over issues — not territory. It is as if we really went to war to bring Iraq democracy.

That is, I think, a laughable proposition.

Most wars are over territory. Hence, the cost of diverting productive resources for, say, the British in 1765, fighting against the French, could be recouped by the seizure of territories — for instance, islands dominated by the sugar cane industry — that would pay back the cost of the war. Plus block competition from another power.

That twentieth century wars are justified in terms of ideology — creating the socialist brotherhood of man, helping the Aryan race achieve its natural dominance, building democracy in the Middle East, etc. — doesn’t really make a difference. In the past, wars could be justified by converting the heathen. But it was best when the converted heathen then went down into the silver mines and brought up what you’d conquered the territory for in the first place.

The result, of course, has to be judged not just in terms of winning, but also the benefit the victor accrues from winning. Say that the pre-emptive war with Iraq went as planned, as it still might, and the American oil corporations were able to purchase, at rock bottom prices, rights to petroleum production that, given the current state of oil exploration, are going to be increasing in value. Or even that America secures its oil routes, and has a reserve country to fall back upon if, say, the Saudis have trouble.

Pre-emption, then, is a perfect strategy for aggression. As it has been in the past — the U.S. is disinclined to ask itself why it is the most aggressive power on the globe, and has been for some sixty years. It has a pattern of always defending itself by invading other countries — hell, the symbol is that the Department of War is called the Department of Defense. These aggressions, in the nineteenth century, were similarly marked as pre-emptive wars — the acquisition, for instance, of the American Southwest and California was such a pre-emptive war, with Polk simply defending American territory from the presumend continued aggressions of the Mexican army. The recent invasion of Panama, on the other hand, was a war for “democracy”, resulting in the replacement of an American puppet gone bad, Noriega, with a series of farcical oligarchs — but those oligarchs were all pliable to America’s economic interest. The attempt to overthrow Chavez in Venezuala by a coup was clearly anti-democratic, but motivated by oil. And so on.

To do the calculus correctly, then, you need to include two factors:
1. consider the war not in isolation, but as part of series of wars — since the U.S. has engaged in some two hundred various sized interventions in the past fifty years, the calculus would certainly have to include advantages with regard to the next war the Americans engage in;
and 2, territorial acquisition, or some equivalent in terms of economic benefit.

You have a different set of markers to adjudge the war’s rationality if you through in these considerations.

42

ogmb 12.08.04 at 7:48 pm

Dsquared: since wars by definition involve the diversion of productive resources into producing expensive pieces of capital equipment which are delivered to people who don’t want them and then explode, they can’t be positive or zero-sum events. Any war is Pareto dominated by a contract under which both parties agree to the outcome that the war would have produced without fighting.

Pareto dominatedness doesn’t equal irrationality, and negative sum in accounting terms doesn’t mean it’s a negative sum game. You’re also assuming enforcible contracts and a “good” peacetime allocation of resources, neither of which are givens in international relations. But I get the point about war being mutual destruction of resources, therefore a “negative” event. But this doesn’t imply irrationality. Either side, in order to prevent war, would be willing to pay R-P (the delta between peacetime and wartime payoffs) to the other side each round, but on the other hand also faces the prospect getting up to R-P from the other side, so there’s a lot of money on the table to fight over. A decision for war can be rational if discounted expected postwar payoff minus discounted war payoff exceeds discounted payoffs without a war. Since by assumption P < R this requires that both sides’ expected probabilities of winning sum up to more than one–iow, overconfidence. But overconfidence is not necessarily irrational because economic rationality only requires best responses to the expected actions of the other side.

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Thomas 12.08.04 at 7:58 pm

DD–It may be true that preventive wars have a worse record than other kinds of wars, and certainly that is relevant, if true, to those deciding on whether to wage preventive war. The goal is to wage only those preventive wars worth waging (however calculated), and we aren’t helped any if we’re told to avoid all preventive wars because most turn out to be not worth waging. The trick is to identify which ones are and which ones aren’t.

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mpowell 12.08.04 at 8:15 pm

A comment on war being a negative sum game: this only holds for the political actors involved, which is important for game theory reasons but should not extend to being a general criticism of war as some here have implied. The Afghanistan war is an excellent example of a war that has a positive sum potential when we include the wellfare of the people of Afghanistan instead of just the interests of the Taliban ruling them. In the case where a regime is not representing the interests of those being ruled, there is always the possibility of a positive sum when that rulership is changed, be it through internal revolution or war against an external foe. If such a war were never desirable, then revolution against an unjust government would also have to be always undesirable.

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Giles 12.08.04 at 8:41 pm

“ahistorical and moralizing underlying assumption”

I thought that the whole point of rational choice is that it is amoral. The point I’m making is that the plains indians with perfect foresight should have marched 1000 of miles in order to defeat the colonists in 1600 when they could. By allowing 200 years of Baysian updating of the benefits of preemptive action, err they were too late to actually take action.

I’d agree with you though that the rational choice is a pretty silly way to look at whether a war can be justified.

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ogmb 12.08.04 at 8:41 pm

On the “can wars be win-win?” question: First of all we have recognize the fundamental shift that happened between WW1 and WW2: the treaty of Versailles to the Marshall Plan. Versailles was driven by the millenia-old rule of war, To the Victor Go the Spoils. The Marshall Plan on the other hand, rather than transferring assets from loser to winner used Allied money to invest in the defeated Axis countries. The payoff for the victors therefore moved from immediate (by seizing assets) to mediate (by creating allies and estblishing trade partnerships).

Iraq, despite the claims of Halliburton profiteering, was designed as a win-win war. The people who think win-win is impossible implictly assume that the post-war economic order is the same as the pre-war order, only disrupted by loss of human lives and industrial assets. This isn’t true, and the losing side changing its political system is the historical rule rather than the exception. Falkland was a “win-win” war in that it was fairly restricted and it directly lead to the toppling of the Argentine junta, therefore giving the Argentinians at least the possibility to create a better social order than they had before. Afghanistan could have been a win-win if the GWB administration hadn’t prematurely redirected its focus to Iraq.

The problem with thinking of Iraq as a win-win war is that it assumes that 1. dictatorship is the worst kind of social order, and 2. democracies just snap into place once you remove the dictator. At least domestically most dictators are preferable (and come into power as remedies) to absence of social order (aka the Libertarian Utopia), and the key rationale for keeping them in power is to keep the country from slipping into chaos. Even if there is a prospect, there are no guarantees that the post-war social order is better than the pre-war order, so fighting a (preventive) war on a win-win premise should make damn sure that the post-war order (quickly) improves on the status quo. The total blindness of the Rumsfeld-Wolfowitz-Feith fascia to this simple doctrine is the main failing of the current administration in re: Iraq.

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dsquared 12.08.04 at 9:47 pm

economic rationality only requires best responses to the expected actions of the other side

No. That’s a definition of the Nash equilibrium concept. The further statement that Nash equilibrium is an acceptable criterion of “economic rationality” is a key controversy and game theory textbooks are wrong to pretend that it can be settled in favour of one side by a wave of the wand.

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Bucky 12.08.04 at 10:10 pm

ogmb – “The problem with thinking of Iraq as a win-win war…”
The problem with thinking of the “war” in Iraq as a war waged for the officially stated purpose – to unseat a dictator – is that in even the most well-intentioned and rational mind it creates an argument against something that doesn’t exist. It diverts oppositional energy into a cul-de-sac, from which it can’t emerge except in defeat.
Inasmuch as your clear paragraphs emphasize the illogic and danger of what’s been done, and refute the given reasons for it, they help greatly. But it would help even more if you attacked the heart of the matter with that same clarity.
The soldiers on the ground, some of them, may believe we’re there for democracy, the Christmas shoppers at the mall may believe it, but no one in Washington believes that, and very few people in the rest of the world do either.
Too often an otherwise sound thinker pounces on these bogus explanations, like a dog capturing a sock, ignoring the hand that holds it for the sake of the game.

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ogmb 12.08.04 at 11:30 pm

No. That’s a definition of the Nash equilibrium concept.

Both logically and chronologically NE (mutual best response) as a solution concept is an upshot of the economic definition of rationality, not vice versa. Although I agree I should’ve used the more general term consequence rather than response since part of game theory is about shaping the opponent’s responses, not just responding to his/her actions.

I don’t quite follow the “acceptable criterion” point. I’m aware that simple NE is considered insufficient as a solution concept, which explains the plethora of refinements, and I realize there’s a big discrepancy between “economic rationality” and “common-sense rationality”, but I’m not sure which one you’re pointing at.

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Hamilton Lovecraft 12.10.04 at 3:11 am

Since war is a negative sum game, rational decision makers do not fight wars

However, a rational decision maker of post-draftable age may encourage others to fight a war after investing heavily in military hardware manufacturing, with positive-sum result for himself.

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fasteddie 12.10.04 at 3:25 am

Afghanistan is lose-lose only if you cling tightly to the idea that the invasion had nothing to do with 9-11, and if you believe that letting the organization which commited that war crime run the Taliban would not have led to further atrocities against Americans.

Are you assuming that 9-11 was a rational act to be analyzed under this structure? Was the 9-11 attack a win for Al Qaeda?

How has invading Afghanistan helped Americans? 150 dead, many many more injured. There is no security outside of Kabul. Blood and treasure gone. Opium production is up, which hurts more Americans. And Osama was not caught, which certainly leaves the US as a loser. Gathering Intelligence and capturing Osama (without blowing up a bunch of mosques) would have been a big win. But the US had other priorities.

How has invading Afghanistan helped the Afghani people? Certainly the thousands killed are not better off, nor the tens of thousands injured, or related to the killed or injured. Afganistan loses also.

Defintely a lose-lose. By concentrating on Iraq before Afghanistan was done, Bush & co were able to snatch defeat from the jaws of victory. Because Afghanistan has so little to destroy, even it’s loss should not have been that bad.

As for 9/11, it was certainly a win for Al Quaeda, moreso because Bush/Cheney/Rumsfeld let bin Laden go, because they were drooling over Iraqi oilfields, the PNAC wet dream. The conpiracy theorist in me wants to believe this is because the elder Bush is pals with bin Laden’s family (and they’re all old chums with the Saudi royals).

Osama is able to frame the conflict as “Islam under attack” and so is many steps closer to his goal of united Islam and a Caliphate.

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Brian Weatherson 12.10.04 at 3:17 pm

Both logically and chronologically NE (mutual best response) as a solution concept is an upshot of the economic definition of rationality, not vice versa. Although I agree I should’ve used the more general term consequence rather than response since part of game theory is about shaping the opponent’s responses, not just responding to his/her actions.

I’d like to see an argument for that, because I’m pretty sure it isn’t a logical consequence. Several of the reasons for thinking that neither NE, nor any other equilibrium concept, can be derived directly from principles of individual rationality are set out in Bob Stalnaker’s recent work, e.g.

* Robert Stalnaker, “Knowledge, Belief and Counterfactual Reasoning in Games”, Economics and Philosophy. 12(1): 133-163

* Robert Stalnaker, “Extensive and strategic forms: Games and models for games”, Research in Economics (1999) 53, 293–319

* Robert Stalnaker, “Belief Revision in Games: Forward and Backward Induction”, Mathematical Social Sciences, vol. 36

The one-line version is that to get from Bayesian rationality to NE (or anything like it) you need assumptions much stronger than common knowledge of mutual rationality, and those assumptions are, on the whole, wildly implausible even as idealisations. Since in war we have quite a bit _less_ than common knowledge of mutual rationality, the relevance of NE is far from obvious.

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John Quiggin 12.10.04 at 8:43 pm

Thanks for these references, Brian, which I’ll chase. I’m also very sceptical about the Nash equilibrium concept, but I think the initial claim that rational people (in Posner’s sense) don’t engage in avoidable negative sum games is more robust than NE.

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