I demonstrated yesterday how the idea of externalities as defined by the presence of external costs relies on the externality going partially unexplained. External costs are necessarily unexplained because they are unexplainable.
The same thing can be said of Pareto inefficiency. Pareto efficiency means no one has any feasible alternatives that can make them better off without making anyone else worse off. Pareto inefficiency, therefore, means that someone can do something to make themselves better off without making anyone else worse off.
But they don't.
To me the very definition of an economic actor is someone who, when they can make themselves better off, does so. The very definition of inefficiency says that they don't.
There are two ways to reconcile this contradiction:
1. The improving alternative is actually infeasible.
2. The feasible alternative is actually not improving.
Or both, of course. And of course both reconciliations reveal the supposed Pareto inefficiency as Pareto efficiency.
Imagine trying to explain Pareto inefficiency. Suppose someone asked why people don't do the thing that makes them all better off. What could be said in explanation?
I have never seen an explanation myself, despite years of searching. I think it's because Pareto inefficiency can't be explained.
Wednesday, May 27, 2015
Tuesday, May 26, 2015
Externalities as acausal phenomena
Yesterday I discussed how market failure originated as an acausal phenomenon. Externalities are no different.
The basic intuition underlying the idea of externalities is that people impose costs on each other. This is a bit weird since cost, in the economic sense, is necessarily something contained within the choosing individual, but the intuition is understandable. Yet, as is so often the case in economics, unpracticed intuition is not very reliable.
It might seem weird to suggest that economists have treated externalities as acausal phenomena. After all, externalities and the external costs that defines them have a clear cause. Pollution is produced by firms. Careless neighbors reduce the surrounding property values. And so on. One party imposes a cost on another.
Yet Coase showed things are not so simple. Economists had utterly ignored the question of why the seeming victim simply put up with the imposed cost. Externalities, Coase explained, are not caused by one party but by two.
Pre-Coase, economists did not bother to explain half of what is necessary to create an externality. There was the active, choosing party that imposed a cost, and the passive victim whose behavior went unexplained.
Understanding the full cause of externalities allows us to make sense of the concept of external costs, or rather, it allows us to see the nonsense of it. If the "victims" of externalities are passive agents, not really economic actors at all, then it makes some sense to talk of costs being imposed on them. But if they are active economic agents choosing to bear the cost as the best of their alternatives, then the external cost is not external at all. They internalize it.
Maybe it seems like the cost is still created by the "aggressor," even if the "victim" chooses to bear it. This is also wrong. The cost is created by both of them, the aggressor by making smoke, for example, and the victim, by choosing to stay in the smoke-infested area. Nothing external is going on, just two parties choosing their best alternatives based on the costs, which are thus internalized.
From the perspective of the "victim" the externality is clearly irrelevant. Imagine a naturally smokey area that someone chooses to live in for some offsetting benefit. We would all understand that this is no externality, and the cost of the smoke is internalized by its "victim." Why should anything be different if the source of the smoke is unnatural?
The basic intuition underlying the idea of externalities is that people impose costs on each other. This is a bit weird since cost, in the economic sense, is necessarily something contained within the choosing individual, but the intuition is understandable. Yet, as is so often the case in economics, unpracticed intuition is not very reliable.
It might seem weird to suggest that economists have treated externalities as acausal phenomena. After all, externalities and the external costs that defines them have a clear cause. Pollution is produced by firms. Careless neighbors reduce the surrounding property values. And so on. One party imposes a cost on another.
Yet Coase showed things are not so simple. Economists had utterly ignored the question of why the seeming victim simply put up with the imposed cost. Externalities, Coase explained, are not caused by one party but by two.
Pre-Coase, economists did not bother to explain half of what is necessary to create an externality. There was the active, choosing party that imposed a cost, and the passive victim whose behavior went unexplained.
Understanding the full cause of externalities allows us to make sense of the concept of external costs, or rather, it allows us to see the nonsense of it. If the "victims" of externalities are passive agents, not really economic actors at all, then it makes some sense to talk of costs being imposed on them. But if they are active economic agents choosing to bear the cost as the best of their alternatives, then the external cost is not external at all. They internalize it.
Maybe it seems like the cost is still created by the "aggressor," even if the "victim" chooses to bear it. This is also wrong. The cost is created by both of them, the aggressor by making smoke, for example, and the victim, by choosing to stay in the smoke-infested area. Nothing external is going on, just two parties choosing their best alternatives based on the costs, which are thus internalized.
From the perspective of the "victim" the externality is clearly irrelevant. Imagine a naturally smokey area that someone chooses to live in for some offsetting benefit. We would all understand that this is no externality, and the cost of the smoke is internalized by its "victim." Why should anything be different if the source of the smoke is unnatural?
Monday, May 25, 2015
Acausal phenomena in economics
Scott Sumner points out how strange it is that many economists take for granted macroeconomic instability. One would think that knowing the cause of macroeconomic instability is crucial to achieving macroeconomic stability, yet economists are often content to accept the instability as simply a fact of life and look for crude solutions.
The same thing happens in welfare economics. In Pigou's seminal The Economics of Welfare, he describes many situations in which markets fail to achieve the optimal outcome. One example is congestion on roads. Marginal cost pricing would yield the optimal amount of congestion on the roads, yet marginal cost pricing is not used, QED. Not long after, in 1924, Frank Knight showed that Pigou was missing a critical piece to his argument: the cause of the supposed inefficiency. Here is Knight, page 12 of the pdf:
By and large Knight's argument was ignored. Then, 40 years later after The Economics of Welfare, Ronald Coase gave a more general version of the same argument, that Pigou failed to see that so-called externalities are caused by the deliberate decision to create and tolerate them because the alternative is too costly, specifically because of transaction costs. Internalizing the externalities, whatever that means, would not be Pareto improving due to the additional constraints Pigou was unaware of.
Knight and Coase were geniuses, but every economist should have wondered the same. By definition inefficiency means that there is some feasible way to make everyone better off. The question is why they don't take that feasible, improving alternative. Pigou's explanation, and the explanation the economics profession has accepted, is that of inefficiency or market failure, which is no explanation at all. They shrug their shoulders, announce that someone or something "failed" (who failed? Why did they fail?), and talk about the optimal Pigovian tax. In the Pigovian system externalities and inefficiency are acausal. They happen, we accept that, and move on.
Asking why of the Pigovian system is fatal to it. There can only be two answers to the question of why inefficiency exists:
1. The Pareto improvement is not feasible.
2. The Pareto improvement is not a Pareto improvement.
Both these answers resolve the confusion of why people aren't taking the opportunity to make themselves better off. They also resolve the inefficiency itself.
Treating economic phenomena as acausal yields the opposite conclusions of treating the same phenomena as causal. Personally, I think the latter method is the way to go.
The same thing happens in welfare economics. In Pigou's seminal The Economics of Welfare, he describes many situations in which markets fail to achieve the optimal outcome. One example is congestion on roads. Marginal cost pricing would yield the optimal amount of congestion on the roads, yet marginal cost pricing is not used, QED. Not long after, in 1924, Frank Knight showed that Pigou was missing a critical piece to his argument: the cause of the supposed inefficiency. Here is Knight, page 12 of the pdf:
Professor Pigou's logic in regard to the roads is, as logic, quite unexceptionable. Its weakness is one frequently met with in economic theorizing, namely that the assumptions diverge in essential respects from the facts of real economic situations. The most essential feature of competitive conditions is reversed, the feature namely, of the private ownership of the factors practically significant for production. If the roads are assumed to be subject to private appropriation and exploitation, precisely the ideal situation which would be established by the imaginary [Pigovian] tax will be brought about through the operation of ordinary economic motives.Knight goes on to explain in detail how the roads would achieve the optimal pricing system under private ownership and competition. Pigou didn't describe inefficiency. He observed the consequences of a missing piece of a well-functioning economic system, namely private ownership.
By and large Knight's argument was ignored. Then, 40 years later after The Economics of Welfare, Ronald Coase gave a more general version of the same argument, that Pigou failed to see that so-called externalities are caused by the deliberate decision to create and tolerate them because the alternative is too costly, specifically because of transaction costs. Internalizing the externalities, whatever that means, would not be Pareto improving due to the additional constraints Pigou was unaware of.
Knight and Coase were geniuses, but every economist should have wondered the same. By definition inefficiency means that there is some feasible way to make everyone better off. The question is why they don't take that feasible, improving alternative. Pigou's explanation, and the explanation the economics profession has accepted, is that of inefficiency or market failure, which is no explanation at all. They shrug their shoulders, announce that someone or something "failed" (who failed? Why did they fail?), and talk about the optimal Pigovian tax. In the Pigovian system externalities and inefficiency are acausal. They happen, we accept that, and move on.
Asking why of the Pigovian system is fatal to it. There can only be two answers to the question of why inefficiency exists:
1. The Pareto improvement is not feasible.
2. The Pareto improvement is not a Pareto improvement.
Both these answers resolve the confusion of why people aren't taking the opportunity to make themselves better off. They also resolve the inefficiency itself.
Treating economic phenomena as acausal yields the opposite conclusions of treating the same phenomena as causal. Personally, I think the latter method is the way to go.
Sunday, May 24, 2015
The opportunity cost of reflecting opportunity costs
Commenter J-D asks an interesting question of John Quiggin: when economists say that prices don't reflect the full opportunity costs, whose opportunity costs do they not reflect?
Society is not a good answer because societies do not choose. So who is being left out?
The opportunity cost of a choice is the best alternative not taken. It is inherently tied to the choice of the individual: the opportunity cost to me of someone else choosing not to give me a dollar is not one dollar. The opportunity cost to me is not even zero: I made no choice and thus bore no opportunity cost.
In welfare economics, prices reflecting all the opportunity costs means that all the net utility has been squeezed out of some constrained choice. Prices ideally encourage people to do as much of something as makes everyone better off and to encourage them to pursue alternatives once doing that thing can no longer make everyone better off. What this requires is that the price of every good and service be equal to the marginal cost of consuming it.
Frankly I think P = MC is a really confusing idea. P is in dollars, and MC is in utils. How are they be compared? Prices "reflect" opportunity cost. What does that mean? I know what it means at extrema, but if we are not at an extremum, as John posits, then the idea just confuses me.
We could speak about prices reflecting opportunity costs if we could translate every MC into a P via a market. That would require complete markets, which is certainly not the case if we are talking about market failure. So while I can make sense of optimality in these terms, I can't make sense of suboptimality. Efficiency makes sense, but inefficiency does not.
I suggested in the comments that normally in economics opportunity cost refers to the best foregone alternative in some choice, but in welfare economics opportunity cost is not tied to choice at all. Rather, when we speak of an opportunity cost to society, and so presumably when we speak of prices failing to reflect opportunity costs, we simply refer to some alternative imaginable arrangement of resources. There is an opportunity cost to society, not because society made a choice, thus forgoing its next-best alternative, but because things could be another way.
This runs contrary to the normal meaning of opportunity cost. Normally opportunity cost has no existence in being but only in doing. (Later I will argue that Pigou in fact intended no contradiction. His use of opportunity cost is the normal use of opportunity cost, or at least it is an attempt to be.)
Not just any imaginable superior alternative is supposed to be proof that prices don't reflect opportunity cost. Only a mere rearrangement of resources is. That is, imagining how better off we would be with cheaper steel is not proof of market failure. But being able to imagine that steel could be reallocated to the benefit of all is proof of market failure.
As I suggest above, market failure (prices not reflecting full opportunity costs) only makes sense in the context of complete markets. This isn't as bad as it sounds. We've learned a thing or two about the creation of markets since Pigou. In particular, we've learned that markets don't exist because making them exist is costly. In other words, there is a true and meaningful sense in which all markets exist...but most of them are too expensive to buy from.
So why don't prices reflect all opportunity costs? Because doing so is costly. Therefore, is it wrong to say that prices do reflect all opportunity costs, including the cost of reflecting opportunity costs?
What does this say about treating market failure as a misallocation of resources? When the supply of steel is less than infinite, there is no misallocation of resources even though everyone could be made better off if the supply of steel were infinite. When the supply of markets is less than infinite, that suggests the choices necessary to achieve the imagined superior alternative allocation of resources costs more than the imagined alternative would yield in benefits if realized. In fact, that is just what Coase demonstrated in his famous 1960 paper, "The Problem of Social Cost."
Moving from scarcity of steel to abundance of steel is a Pareto improvement, but infeasible, and thus efficient. Moving from scarcity of markets to abundance of markets is a Pareto improvement, but infeasible. Why is it inefficient?
More on this to come.
Society is not a good answer because societies do not choose. So who is being left out?
The opportunity cost of a choice is the best alternative not taken. It is inherently tied to the choice of the individual: the opportunity cost to me of someone else choosing not to give me a dollar is not one dollar. The opportunity cost to me is not even zero: I made no choice and thus bore no opportunity cost.
In welfare economics, prices reflecting all the opportunity costs means that all the net utility has been squeezed out of some constrained choice. Prices ideally encourage people to do as much of something as makes everyone better off and to encourage them to pursue alternatives once doing that thing can no longer make everyone better off. What this requires is that the price of every good and service be equal to the marginal cost of consuming it.
Frankly I think P = MC is a really confusing idea. P is in dollars, and MC is in utils. How are they be compared? Prices "reflect" opportunity cost. What does that mean? I know what it means at extrema, but if we are not at an extremum, as John posits, then the idea just confuses me.
We could speak about prices reflecting opportunity costs if we could translate every MC into a P via a market. That would require complete markets, which is certainly not the case if we are talking about market failure. So while I can make sense of optimality in these terms, I can't make sense of suboptimality. Efficiency makes sense, but inefficiency does not.
I suggested in the comments that normally in economics opportunity cost refers to the best foregone alternative in some choice, but in welfare economics opportunity cost is not tied to choice at all. Rather, when we speak of an opportunity cost to society, and so presumably when we speak of prices failing to reflect opportunity costs, we simply refer to some alternative imaginable arrangement of resources. There is an opportunity cost to society, not because society made a choice, thus forgoing its next-best alternative, but because things could be another way.
This runs contrary to the normal meaning of opportunity cost. Normally opportunity cost has no existence in being but only in doing. (Later I will argue that Pigou in fact intended no contradiction. His use of opportunity cost is the normal use of opportunity cost, or at least it is an attempt to be.)
Not just any imaginable superior alternative is supposed to be proof that prices don't reflect opportunity cost. Only a mere rearrangement of resources is. That is, imagining how better off we would be with cheaper steel is not proof of market failure. But being able to imagine that steel could be reallocated to the benefit of all is proof of market failure.
As I suggest above, market failure (prices not reflecting full opportunity costs) only makes sense in the context of complete markets. This isn't as bad as it sounds. We've learned a thing or two about the creation of markets since Pigou. In particular, we've learned that markets don't exist because making them exist is costly. In other words, there is a true and meaningful sense in which all markets exist...but most of them are too expensive to buy from.
So why don't prices reflect all opportunity costs? Because doing so is costly. Therefore, is it wrong to say that prices do reflect all opportunity costs, including the cost of reflecting opportunity costs?
What does this say about treating market failure as a misallocation of resources? When the supply of steel is less than infinite, there is no misallocation of resources even though everyone could be made better off if the supply of steel were infinite. When the supply of markets is less than infinite, that suggests the choices necessary to achieve the imagined superior alternative allocation of resources costs more than the imagined alternative would yield in benefits if realized. In fact, that is just what Coase demonstrated in his famous 1960 paper, "The Problem of Social Cost."
Moving from scarcity of steel to abundance of steel is a Pareto improvement, but infeasible, and thus efficient. Moving from scarcity of markets to abundance of markets is a Pareto improvement, but infeasible. Why is it inefficient?
More on this to come.
Saturday, May 23, 2015
If utility did not exist, it would be necessary to invent it
A very common myth, even one perpetuated by economists, is that utility means happiness, pleasure, satisfaction, the avoidance of pain, or something like those things. That is not what utility means.
To understand and predict behavior, we need to know what people value. For example, will Alice choose green beans or asparagus? That depends on which one she values more. Why did Bob willingly tire himself and expend energy at the gym? Because he values being fit. Instantly we run into two problems:
1. We don't know what people's values are.
2. People value different things.
Most people's values clearly include things like happiness, pleasure, satisfaction, and the avoidance of pain. But there are people who eschew earthly pleasure. There are people who's self-destructive behavior seems almost deliberately aimed at preventing their own happiness. People willingly bear pain for many purposes and even seek pain and painful experiences out, whether something drastic and worrying like cutting themselves, or something more mundane to a degree like punishing themselves at the gym, or even emotional pain like calling up that ex-lover. (See What Do People Want to Feel and Why?) Are all these people and their actions outside the scope of economics?
It is also a mistake to think that all values have to be sensations. Sometimes people make the mistake of thinking that death must carry infinite negative utility. That would be true if the only values were bodily sensations. However, people can also value things external to themselves, like the lives of their children or comrades, even at the expense of being able to feel bodily sensations about them. People suffer and sacrifice to write a novel, to start a business, to build a house, to create democracy, to help the impoverished and the victims of earthquakes, famines, and wars. Are all these people and their actions outside the scope of economics?
People are not happiness maximizers, pain minimizers, pleasure optimizers, or any other such thing, although particular individuals might be. We need a word that simultaneously expresses our ignorance in a concise manner and unites the many diverse values under the economizing paradigm. That word is utility. That way people don't say, "But what are people maximizing?" because a scientific-sounding answer exists, and they don't say, "Economics might work for those values, but it doesn't work for my values," because utility is a placeholder for any value. And that is very important and necessary, but it has clearly caused some confusion among economists.
Interpersonal utility comparisons are impossible not because of some property of utility, because utility has no properties. Utility is not even nothing. It is not a thing. It is a mere placeholder, simultaneously expressing our ignorance of people's values and the proposition that the pursuit of values in general has certain general properties, regardless of the particular value. Interpersonal utility comparisons are impossible because you can't compare [placeholder for ignorance and the idea that all values fit into the economizing paradigm] between people. Rather, you must know that people have the same values, which you very rarely do.
Here's a question for economists who think utility means happiness or some other particular value: if scientists discovered a planet full of sadness maximizers, would you think that the utility maximization paradigm does not apply to them?
To understand and predict behavior, we need to know what people value. For example, will Alice choose green beans or asparagus? That depends on which one she values more. Why did Bob willingly tire himself and expend energy at the gym? Because he values being fit. Instantly we run into two problems:
1. We don't know what people's values are.
2. People value different things.
Most people's values clearly include things like happiness, pleasure, satisfaction, and the avoidance of pain. But there are people who eschew earthly pleasure. There are people who's self-destructive behavior seems almost deliberately aimed at preventing their own happiness. People willingly bear pain for many purposes and even seek pain and painful experiences out, whether something drastic and worrying like cutting themselves, or something more mundane to a degree like punishing themselves at the gym, or even emotional pain like calling up that ex-lover. (See What Do People Want to Feel and Why?) Are all these people and their actions outside the scope of economics?
It is also a mistake to think that all values have to be sensations. Sometimes people make the mistake of thinking that death must carry infinite negative utility. That would be true if the only values were bodily sensations. However, people can also value things external to themselves, like the lives of their children or comrades, even at the expense of being able to feel bodily sensations about them. People suffer and sacrifice to write a novel, to start a business, to build a house, to create democracy, to help the impoverished and the victims of earthquakes, famines, and wars. Are all these people and their actions outside the scope of economics?
People are not happiness maximizers, pain minimizers, pleasure optimizers, or any other such thing, although particular individuals might be. We need a word that simultaneously expresses our ignorance in a concise manner and unites the many diverse values under the economizing paradigm. That word is utility. That way people don't say, "But what are people maximizing?" because a scientific-sounding answer exists, and they don't say, "Economics might work for those values, but it doesn't work for my values," because utility is a placeholder for any value. And that is very important and necessary, but it has clearly caused some confusion among economists.
Interpersonal utility comparisons are impossible not because of some property of utility, because utility has no properties. Utility is not even nothing. It is not a thing. It is a mere placeholder, simultaneously expressing our ignorance of people's values and the proposition that the pursuit of values in general has certain general properties, regardless of the particular value. Interpersonal utility comparisons are impossible because you can't compare [placeholder for ignorance and the idea that all values fit into the economizing paradigm] between people. Rather, you must know that people have the same values, which you very rarely do.
Here's a question for economists who think utility means happiness or some other particular value: if scientists discovered a planet full of sadness maximizers, would you think that the utility maximization paradigm does not apply to them?
Friday, May 22, 2015
The conditions for doing interpersonal utility comparisons
Utility is a deliberately obfuscating concept, so it's not surprising that even economists find interpersonal utility comparisons a bit confusing (see the comments on the last link).
The maximization/optimization paradigm (henceforth just maximization) is very useful and seems like it must be true somehow, or at least is the best way to understand economic phenomena. But then the question is, what are people maximizing? The truth is, we don't know. It's awkward and embarrassing to say "people are I-don't-know-what maximizers," so we say "people are utility maximizers." It's a concise and scientific way of expressing our ignorance.
Utility is not happiness. If we thought people were happiness maximizers, we would say they are happiness maximizers. Utility is not pleasure, or satisfaction, or eudaimonia, or anything else. Utility is utility, a code word for ignorance.
That is why interpersonal utility comparisons are impossible. It isn't because utility is ordinal rather than cardinal. That just assumes the conclusion, that utility is something that can't be compared across people. Rather, IUCs are impossible because there is no sense in which Alice can have more I-don't-know-what than Bob.
We can say that Alice has more happiness than Bob. We can say that Bob has more money than Alice. We can say that Alice has more satisfaction than Bob, and we can say that Bob has more pleasure than Alice. All these comparisons are perfectly valid. But I-don't-know-what? Calling that comparison impossible gives it too much credit. It just doesn't make sense.
Many economists don't know this. They talk about how IUCs might be possible in the future as we learn more about the brain, as if utility is a real thing. Utility is not a real thing. It is a placeholder for ignorance.
So IUCs are not even coherent enough to be impossible. Yet there is this intuition that a poor person gets more utility from a dollar than a rich person. Let's explore this. First of all, on most comparisons of any particular value, the poor person gains more than the rich person from the marginal dollar. The poor person gains more happiness, pleasure, relief, etc., than the rich person in most circumstances. If you replace the placeholder of utility with something concrete, comparisons are valid. This isn't an interpersonal utility comparison, it is an interpersonal happiness//pleasure/relief comparison.
Note that you can't always do this. For example, who gets wealthier from an additional dollar, the poor person or the rich person? Obviously neither.
This possibility shows that substituting any particular value for the utility placeholder does not necessarily get us to the intuition that a poor person gets more utility from an additional dollar than a rich person. People necessarily maximize utility. Utility is the thing people are maximizing. But people do not have to be, say, happiness maximizers, and they often are not. So even if utility were a more substantial concept, any particular thing poor people gain more of than rich people do from an additional dollar would not necessarily maximize utility if people are not trying to maximize that value. And since poor people cannot gain more of every possible value than rich people from an additional dollar (e.g. wealth), then simply knowing what specific value utility is a placeholder for is insufficient to generate our intuition that giving a poor person an additional dollar generates more utility than giving it to a rich person.
Here is another problem: people want different things. If the poor person is a happiness maximizer, and the rich person is a satisfaction, then the comparison is again not even impossible. There is no sense in which a dollar can give a poor person more happiness than it gives a rich person satisfaction. The comparison is only valid if both individuals are trying to maximize the same thing.
So this is what we need to do an interpersonal utility comparison: we need to know what utility is a placeholder for, and we need to know that utility is a placeholder for the same thing for both individuals. Having both of these conditions together is unlikely, to put it mildly.
Yet it really does seem that giving a poor person a dollar generates more utility than giving a rich person a dollar. There is one sense in which this intuition is unambiguously and easily true. If you choose to give a dollar to a poor person rather than give it to a rich person, then giving a poor person a dollar does generate more utility than giving a rich person a dollar. It generates more utility for you!
Most people would rather see a poor person get another dollar than a richer person, even most rich people. Maybe that is because we care about happiness, and a poor person is happier from an additional dollar than a rich person (the fact that neither might be happiness maximizers is happily irrelevant). For many other values we likely share, that argument is true. Thus it is true that what is valuable and good is enhanced more by giving an additional dollar to a poor person than a rich person, and this is because the poor person is made happier/more satisfied/whatever than the rich person by the additional dollar, even though the interpersonal utility comparison is impossible.
The maximization/optimization paradigm (henceforth just maximization) is very useful and seems like it must be true somehow, or at least is the best way to understand economic phenomena. But then the question is, what are people maximizing? The truth is, we don't know. It's awkward and embarrassing to say "people are I-don't-know-what maximizers," so we say "people are utility maximizers." It's a concise and scientific way of expressing our ignorance.
Utility is not happiness. If we thought people were happiness maximizers, we would say they are happiness maximizers. Utility is not pleasure, or satisfaction, or eudaimonia, or anything else. Utility is utility, a code word for ignorance.
That is why interpersonal utility comparisons are impossible. It isn't because utility is ordinal rather than cardinal. That just assumes the conclusion, that utility is something that can't be compared across people. Rather, IUCs are impossible because there is no sense in which Alice can have more I-don't-know-what than Bob.
We can say that Alice has more happiness than Bob. We can say that Bob has more money than Alice. We can say that Alice has more satisfaction than Bob, and we can say that Bob has more pleasure than Alice. All these comparisons are perfectly valid. But I-don't-know-what? Calling that comparison impossible gives it too much credit. It just doesn't make sense.
Many economists don't know this. They talk about how IUCs might be possible in the future as we learn more about the brain, as if utility is a real thing. Utility is not a real thing. It is a placeholder for ignorance.
So IUCs are not even coherent enough to be impossible. Yet there is this intuition that a poor person gets more utility from a dollar than a rich person. Let's explore this. First of all, on most comparisons of any particular value, the poor person gains more than the rich person from the marginal dollar. The poor person gains more happiness, pleasure, relief, etc., than the rich person in most circumstances. If you replace the placeholder of utility with something concrete, comparisons are valid. This isn't an interpersonal utility comparison, it is an interpersonal happiness//pleasure/relief comparison.
Note that you can't always do this. For example, who gets wealthier from an additional dollar, the poor person or the rich person? Obviously neither.
This possibility shows that substituting any particular value for the utility placeholder does not necessarily get us to the intuition that a poor person gets more utility from an additional dollar than a rich person. People necessarily maximize utility. Utility is the thing people are maximizing. But people do not have to be, say, happiness maximizers, and they often are not. So even if utility were a more substantial concept, any particular thing poor people gain more of than rich people do from an additional dollar would not necessarily maximize utility if people are not trying to maximize that value. And since poor people cannot gain more of every possible value than rich people from an additional dollar (e.g. wealth), then simply knowing what specific value utility is a placeholder for is insufficient to generate our intuition that giving a poor person an additional dollar generates more utility than giving it to a rich person.
Here is another problem: people want different things. If the poor person is a happiness maximizer, and the rich person is a satisfaction, then the comparison is again not even impossible. There is no sense in which a dollar can give a poor person more happiness than it gives a rich person satisfaction. The comparison is only valid if both individuals are trying to maximize the same thing.
So this is what we need to do an interpersonal utility comparison: we need to know what utility is a placeholder for, and we need to know that utility is a placeholder for the same thing for both individuals. Having both of these conditions together is unlikely, to put it mildly.
Yet it really does seem that giving a poor person a dollar generates more utility than giving a rich person a dollar. There is one sense in which this intuition is unambiguously and easily true. If you choose to give a dollar to a poor person rather than give it to a rich person, then giving a poor person a dollar does generate more utility than giving a rich person a dollar. It generates more utility for you!
Most people would rather see a poor person get another dollar than a richer person, even most rich people. Maybe that is because we care about happiness, and a poor person is happier from an additional dollar than a rich person (the fact that neither might be happiness maximizers is happily irrelevant). For many other values we likely share, that argument is true. Thus it is true that what is valuable and good is enhanced more by giving an additional dollar to a poor person than a rich person, and this is because the poor person is made happier/more satisfied/whatever than the rich person by the additional dollar, even though the interpersonal utility comparison is impossible.
Thursday, May 21, 2015
Should you prefer inefficiency to efficiency?
Suppose World 1 is efficient, and you are happy/satisfied/whatever to the tune of 100 utils. Suppose World 2 is inefficient, and you are happy/satisfied/whatever to the tune of 100 utils. Which world should you choose to live in?
The inefficient world, of course. By definition some feasible yet unexploited Pareto improvement exists in the inefficient world, but not in the efficient world. Therefore you can hop into the inefficient world, get the Pareto improvement, and be better off than you would be in World 1. In fact, the more inefficient World 2 is, the more otherwise superior World 1 would have to be for you to be indifferent between the two.
Maybe it seems like cheating to have World 1 be no better than World 2. After all, efficiency versus inefficiency suggests the former should be better. But that's not how efficiency is defined. Efficiency just means that there are no unexploited feasible Pareto improvements. It doesn't say anything about how well a system accomplishes anything or how well-off anyone is. And while it's true that the efficient state resulting from a Pareto improvement in an inefficient state is superior to the inefficient state, so is the efficient state resulting from a Pareto improvement in an efficient state (e.g. a technological improvement dropped into a system of perfect competition). And an inefficient state resulting from a Pareto improvement in an efficient state is superior to the efficient state (e.g. a technological improvement dropped into a system of perfect competition that leads to some degree of market power in some firms).
The inefficient world, of course. By definition some feasible yet unexploited Pareto improvement exists in the inefficient world, but not in the efficient world. Therefore you can hop into the inefficient world, get the Pareto improvement, and be better off than you would be in World 1. In fact, the more inefficient World 2 is, the more otherwise superior World 1 would have to be for you to be indifferent between the two.
Maybe it seems like cheating to have World 1 be no better than World 2. After all, efficiency versus inefficiency suggests the former should be better. But that's not how efficiency is defined. Efficiency just means that there are no unexploited feasible Pareto improvements. It doesn't say anything about how well a system accomplishes anything or how well-off anyone is. And while it's true that the efficient state resulting from a Pareto improvement in an inefficient state is superior to the inefficient state, so is the efficient state resulting from a Pareto improvement in an efficient state (e.g. a technological improvement dropped into a system of perfect competition). And an inefficient state resulting from a Pareto improvement in an efficient state is superior to the efficient state (e.g. a technological improvement dropped into a system of perfect competition that leads to some degree of market power in some firms).
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