What do we mean by “obesity”?

Nov 25 JDN 2458448

I thought this topic would be particularly appropriate for the week of Thanksgiving, since as a matter of public ritual, this time every year, we eat too much and don’t get enough exercise.

No doubt you have heard the term “obesity epidemic”: It’s not just used by WebMD or mainstream news; it’s also used by the American Heart Association, the Center for Disease Control, the World Health Organization, and sometimes even published in peer-reviewed journal articles.

This is kind of weird, because the formal meaning of the term “epidemic” clearly does not apply here. I feel uncomfortable going against public health officials in what is clearly their area of expertise rather than my own, but everything I’ve ever read about the official definition of the word “epidemic” requires it to be an infectious disease. You can’t “catch” obesity. Hanging out with people who are obese may slightly raise your risk of obesity, but not in the way that hanging out with people with influenza gives you influenza. It’s not caused by bacteria or viruses. Eating food touched by a fat person won’t cause you to catch the fat. Therefore, whatever else it is, this is not an epidemic. (I guess sometimes we use the term more metaphorically, “an epidemic of bankruptcies” or an “epidemic of video game consumption”; but I feel like the WHO and CDC of all people should be more careful.)

Indeed, before we decide what exactly this is, I think we should first ask ourselves a deeper question: What do we mean by “obesity”?

The standard definition of “obesity” relies upon the body mass index (BMI), a very crude measure that simply takes your body mass and divides by the square of your height. It’s easy to measure, but that’s basically its only redeeming quality.

Anyone who has studied dimensional analysis should immediately see a problem here: That isn’t a unit of density. It’s a unit of… density-length? If you take the exact same individual and scale them up by 10%, their BMI will increase by 10%. Do we really intend to say that simply being larger makes you obese, for the exact same ratios of muscle, fat, and bone?

Because of this, the taller you are, the more likely your BMI is going to register as “obese”, holding constant your actual level of health and fitness. And worldwide, average height has been increasing. This isn’t enough to account for the entire trend in rising BMI, but it reduces it substantially; average height has increased by about 10% since the 1950s, which is enough to raise our average BMI by about 2 points of the 5-point observed increase.

And of course BMI doesn’t say anything about your actual ratios of fat and muscle; all it says is how many total kilograms are in your body. As a result, there is a systematic bias against athletes in the calculation of BMI—and any health measure that is biased against athletes is clearly doing something wrong. All those doctors telling us to exercise more may not realize it, but if we actually took their advice, our BMIs would very likely get higher, not lower—especially for men, especially for strength-building exercise.

It’s also quite clear that our standards for “healthy weight” are distorted by social norms. Feminists have been talking about this for years; most women will never look like supermodels no matter how much weight they lose—and eating disorders are much more dangerous than being even 50 pounds overweight. We’re starting to figure out that similar principles hold for men: A six-pack of abs doesn’t actually mean you’re healthy; it means you are dangerously depleted of fatty acids.

To compensate for this, it seems like the most sensible methodology would be to figure out empirically what sort of weight is most strongly correlated with good health and long lifespan—what BMI maximizes your expected QALY.

You might think that this is what public health officials did when defining what is currently categorized as “normal weight”—but you would be wrong. They used social norms and general intuition, and as a result, our standards for “normal weight” are systematically miscalibrated.

In fact, the empirical evidence is quite clear: The people with the highest expected QALY are those who are classified as “overweight”, with BMI between 25 and 30. Those of “normal weight” (20 to 25) fare slightly worse, followed by those classified as “obese class I” (30 to 35)—but we don’t actually see large effects until either “underweight” (18.5-20) or “obese class II” (35 to 40). And the really severe drops in life and health expectancy don’t happen until “obese class III” (>40); and we see the same severe drops at “very underweight” (<18.5).
With that in mind, consider that the global average BMI increased from 21.7 in men and 21.4 in women in 1975 to 24.2 in men and 24.4 in women in 2014. That is, the world average increased from the low end of “normal weight” which is actually too light, to the high end of “normal weight” which is probably optimal. The global prevalence of “morbid obesity”, the kind that actually has severely detrimental effects on health, is only 0.64% in men and 1.6% in men. Even including “severe obesity”, the kind that has a noticeable but not dramatic effect on health, is only 2.3% in men and 5.0% in women. That’s your epidemic? Reporting often says things like “2/3 of American adults are overweight or obese”; but all that “overweight” proportion should be utterly disregarded, since it is beneficial to health. The actual prevalence of obesity in the US—even including class I obesity which is not very harmful—is less than 40%.

If obesity were the health crisis it were made out to be, we should expect that global life expectancy is decreasing, or at the very least not increasing. On the contrary, it is rapidly increasing: In 1955, global life expectancy was only 55 years, while it is now over 70.

Worldwide, the countries with the highest obesity rates are those with the longest life expectancy, because both of these things are strongly correlated with high levels of economic development. But it may not just be that: Smoking reduces obesity while also reducing lifespan, and a lot of those countries with very high obesity (including the US) have very low rates of smoking.

There’s some evidence that within the set of rich, highly-developed countries, obesity rates are positively correlated with lower life expectancy, but these effects are much smaller than the effects of high development itself. Going from the highest obesity in the world (the US, of course) to the lowest among all highly-developed countries (Japan) requires reducing the obesity rate by 34 percentage points but only increases life expectancy by about 5 years. You’d get the same increase by raising overall economic development from the level of Turkey to the level of Greece, about 10 points on the 100-point HDI scale.

 

Now, am I saying that we should all be 400 pounds? No, there does come a point where excess weight is clearly detrimental to health. But this threshold is considerably higher than you have probably been led to believe. If you are 15 or 20 pounds “overweight” by what our society (or even your doctor!) tells you, you are probably actually at the optimal weight for your body type. If you are 30 or 40 pounds “overweight”, you may want to try to lose some weight, but don’t make yourself suffer to achieve it. Only if you are 50 pounds or more “overweight” should you really be considering drastic action. If you do try to lose weight, be realistic about your goal: Losing 5% to 10% of your initial weight is a roaring success.

There are also reasons to be particularly concerned about obesity and lack of exercise in children, which is why Michelle Obama’s “Let’s Move!” campaign was a good thing.

And yes, exercise more! Don’t do it to try to lose weight (exercise does not actually cause much weight loss). Just do it. Exercise has so many health benefits it’s honestly kind of ridiculous.

But why am I complaining about this, anyway? Even if we cause some people to worry more about eating less than is strictly necessary, what’s the harm in that? At least we’re getting people to exercise, and Thanksgiving was already ruined by politics anyway.

Well, here’s the thing: I don’t think this obesity panic is actually making us any less obese.

The United States is the most obese country in the world—and you can’t so much as call up Facebook or step into a subway car in the US without someone telling you that you’re too fat and you need to lose weight. The people who really are obese and may need medical help losing weight are the ones most likely to be publicly shamed and harassed for their weight—and there’s no evidence that this actually does anything to reduce their weight. People who experience shaming and harassment for their weight are actually less likely to achieve sustained weight loss.

Teenagers—both boys and girls—who are perceived to be “overweight” are at substantially elevated risk of depression and suicide. People who more fully internalize feelings of shame about their weight have higher blood pressure and higher triglicerides, though once you control for other factors the effect is not huge. There’s even evidence that fat shaming by medical professionals leads to worse treatment outcomes among obese patients.

If we want to actually reduce obesity—and this makes sense, at least for the upper-tail obesity of BMI above 35—then we should be looking at what sort of interventions are actually effective at doing that. Medicine has an important role to play of course, but I actually think economics might be stronger here (though I suppose I would, wouldn’t I?).

Number 1: Stop subsidizing meat and feed grains. There is now quite clear evidence that direct and indirect government subsidies for meat production are a contributing factor in our high fat consumption and thus high obesity rate, though obviously other factors matter too. If you’re worried about farmers, subsidize vegetables instead, or pay for active labor market programs that will train those farmers to work in new industries. This thing we do where we try to save the job instead of the worker is fundamentally idiotic and destructive. Jobs are supposed to be destroyed; that’s what technological improvement is. If you stop destroying jobs, you will stop economic growth.

Number 2: Restrict advertising of high-sugar, high-fat foods, especially to children. Food advertising is particularly effective, because it draws on such primal impulses, and children are particularly vulnerable (as the APA has publicly reported on, including specifically for food advertising). Corporations like McDonald’s and Kellogg’s know quite well what they’re doing when they advertise high-fat, high-sugar foods to kids and get them into the habit of eating them early.

Number 3: Find policies to promote exercise. Despite its small effects on weight loss, exercise has enormous effects on health. Indeed, the fact that people who successfully lose weight show long-term benefits even if they put the weight back on suggests to me that really what they gained was a habit of exercise. We need to find ways to integrate exercise into our daily lives more. The one big thing that our ancestors did do better than we do is constantly exercise—be it hunting, gathering, or farming. Standing desks and treadmill desks may seem weird, but there is evidence that they actually improve health. Right now they are quite expensive, so most people don’t buy them. If we subsidized them, they would be cheaper; if they were cheaper, more people would buy them; if more people bought them, they would seem less weird. Eventually, it could become normative to walk on a treadmill while you work and sitting might seem weird. Even a quite large subsidy could be worthwhile: say we had to spend $500 per person per year to buy every single adult a treadmill desk each year. That comes to about $80 billion per year, which is less than one fourth what we’re currently spending on diabetes or heart disease, so we’d break even if we simply managed to reduce those two conditions by 13%. Add in all the other benefits for depression, chronic pain, sleep, sexual function, and so on, and the quality of life improvement could be quite substantial.

What is progress? How far have we really come?

JDN 2457534

It is a controversy that has lasted throughout the ages: Is the world getting better? Is it getting worse? Or is it more or less staying the same, changing in ways that don’t really constitute improvements or detriments?

The most obvious and indisputable change in human society over the course of history has been the advancement of technology. At one extreme there are techno-utopians, who believe that technology will solve all the world’s problems and bring about a glorious future; at the other extreme are anarcho-primitivists, who maintain that civilization, technology, and industrialization were all grave mistakes, removing us from our natural state of peace and harmony.

I am not a techno-utopian—I do not believe that technology will solve all our problems—but I am much closer to that end of the scale. Technology has solved a lot of our problems, and will continue to solve a lot more. My aim in this post is to convince you that progress is real, that things really are, on the whole, getting better.

One of the more baffling arguments against progress comes from none other than Jared Diamond, the social scientist most famous for Guns, Germs and Steel (which oddly enough is mainly about horses and goats). About seven months before I was born, Diamond wrote an essay for Discover magazine arguing quite literally that agriculture—and by extension, civilization—was a mistake.

Diamond fortunately avoids the usual argument based solely on modern hunter-gatherers, which is a selection bias if ever I heard one. Instead his main argument seems to be that paleontological evidence shows an overall decrease in health around the same time as agriculture emerged. But that’s still an endogeneity problem, albeit a subtler one. Maybe agriculture emerged as a response to famine and disease. Or maybe they were both triggered by rising populations; higher populations increase disease risk, and are also basically impossible to sustain without agriculture.

I am similarly dubious of the claim that hunter-gatherers are always peaceful and egalitarian. It does seem to be the case that herders are more violent than other cultures, as they tend to form honor cultures that punish all sleights with overwhelming violence. Even after the Industrial Revolution there were herder honor cultures—the Wild West. Yet as Steven Pinker keeps trying to tell people, the death rates due to homicide in all human cultures appear to have steadily declined for thousands of years.

I read an article just a few days ago on the Scientific American blog which included the following claim so astonishingly nonsensical it makes me wonder if the authors can even do arithmetic or read statistical tables correctly:

I keep reminding readers (see Further Reading), the evidence is overwhelming that war is a relatively recent cultural invention. War emerged toward the end of the Paleolithic era, and then only sporadically. A new study by Japanese researchers published in the Royal Society journal Biology Letters corroborates this view.

Six Japanese scholars led by Hisashi Nakao examined the remains of 2,582 hunter-gatherers who lived 12,000 to 2,800 years ago, during Japan’s so-called Jomon Period. The researchers found bashed-in skulls and other marks consistent with violent death on 23 skeletons, for a mortality rate of 0.89 percent.

That is supposed to be evidence that ancient hunter-gatherers were peaceful? The global homicide rate today is 62 homicides per million people per year. Using the worldwide life expectancy of 71 years (which is biasing against modern civilization because our life expectancy is longer), that means that the worldwide lifetime homicide rate is 4,400 homicides per million people, or 0.44%—that’s less than half the homicide rate of these “peaceful” hunter-gatherers. If you compare just against First World countries, the difference is even starker; let’s use the US, which has the highest homicide rate in the First World. Our homicide rate is 38 homicides per million people per year, which at our life expectancy of 79 years is 3,000 homicides per million people, or an overall homicide rate of 0.3%, slightly more than a third of this “peaceful” ancient culture. The most peaceful societies today—notably Japan, where these remains were found—have homicide rates as low as 3 per million people per year, which is a lifetime homicide rate of 0.02%, forty times smaller than their supposedly utopian ancestors. (Yes, all of Japan has fewer total homicides than Chicago. I’m sure it has nothing to do with their extremely strict gun control laws.) Indeed, to get a modern homicide rate as high as these hunter-gatherers, you need to go to a country like Congo, Myanmar, or the Central African Republic. To get a substantially higher homicide rate, you essentially have to be in Latin America. Honduras, the murder capital of the world, has a lifetime homicide rate of about 6.7%.

Again, how did I figure these things out? By reading basic information from publicly-available statistical tables and then doing some simple arithmetic. Apparently these paleoanthropologists couldn’t be bothered to do that, or didn’t know how to do it correctly, before they started proclaiming that human nature is peaceful and civilization is the source of violence. After an oversight as egregious as that, it feels almost petty to note that a sample size of a few thousand people from one particular region and culture isn’t sufficient data to draw such sweeping judgments or speak of “overwhelming” evidence.

Of course, in order to decide whether progress is a real phenomenon, we need a clearer idea of what we mean by progress. It would be presumptuous to use per-capita GDP, though there can be absolutely no doubt that technology and capitalism do in fact raise per-capita GDP. If we measure by inequality, modern society clearly fares much worse (our top 1% share and Gini coefficient may be higher than Classical Rome!), but that is clearly biased in the opposite direction, because the main way we have raised inequality is by raising the ceiling, not lowering the floor. Most of our really good measures (like the Human Development Index) only exist for the last few decades and can barely even be extrapolated back through the 20th century.

How about babies not dying? This is my preferred measure of a society’s value. It seems like something that should be totally uncontroversial: Babies dying is bad. All other things equal, a society is better if fewer babies die.

I suppose it doesn’t immediately follow that all things considered a society is better if fewer babies die; maybe the dying babies could be offset by some greater good. Perhaps a totalitarian society where no babies die is in fact worse than a free society in which a few babies die, or perhaps we should be prepared to accept some small amount of babies dying in order to save adults from poverty, or something like that. But without some really powerful overriding reason, babies not dying probably means your society is doing something right. (And since most ancient societies were in a state of universal poverty and quite frequently tyranny, these exceptions would only strengthen my case.)

Well, get ready for some high-yield truth bombs about infant mortality rates.

It’s hard to get good data for prehistoric cultures, but the best data we have says that infant mortality in ancient hunter-gatherer cultures was about 20-50%, with a best estimate around 30%. This is statistically indistinguishable from early agricultural societies.

Indeed, 30% seems to be the figure humanity had for most of history. Just shy of a third of all babies died for most of history.

In Medieval times, infant mortality was about 30%.

This same rate (fluctuating based on various plagues) persisted into the Enlightenment—Sweden has the best records, and their infant mortality rate in 1750 was about 30%.

The decline in infant mortality began slowly: During the Industrial Era, infant mortality was about 15% in isolated villages, but still as high as 40% in major cities due to high population densities with poor sanitation.

Even as recently as 1900, there were US cities with infant mortality rates as high as 30%, though the overall rate was more like 10%.

Most of the decline was recent and rapid: Just within the US since WW2, infant mortality fell from about 5.5% to 0.7%, though there remains a substantial disparity between White and Black people.

Globally, the infant mortality rate fell from 6.3% to 3.2% within my lifetime, and in Africa today, the region where it is worst, it is about 5.5%—or what it was in the US in the 1940s.

This precipitous decline in babies dying is the main reason ancient societies have such low life expectancies; actually once they reached adulthood they lived to be about 70 years old, not much worse than we do today. So my multiplying everything by 71 actually isn’t too far off even for ancient societies.

Let me make a graph for you here, of the approximate rate of babies dying over time from 10,000 BC to today:

Infant_mortality.png

Let’s zoom in on the last 250 years, where the data is much more solid:

Infant_mortality_recent.png

I think you may notice something in these graphs. There is quite literally a turning point for humanity, a kink in the curve where we suddenly begin a rapid decline from an otherwise constant mortality rate.

That point occurs around or shortly before 1800—that is, it occurs at industrial capitalism. Adam Smith (not to mention Thomas Jefferson) was writing at just about the point in time when humanity made a sudden and unprecedented shift toward saving the lives of millions of babies.

So now, think about that the next time you are tempted to say that capitalism is an evil system that destroys the world; the evidence points to capitalism quite literally saving babies from dying.

How would it do so? Well, there’s that rising per-capita GDP we previously ignored, for one thing. But more important seems to be the way that industrialization and free markets support technological innovation, and in this case especially medical innovation—antibiotics and vaccines. Our higher rates of literacy and better communication, also a result of raised standard of living and improved technology, surely didn’t hurt. I’m not often in agreement with the Cato Institute, but they’re right about this one: Industrial capitalism is the chief source of human progress.

Billions of babies would have died but we saved them. So yes, I’m going to call that progress. Civilization, and in particular industrialization and free markets, have dramatically improved human life over the last few hundred years.

In a future post I’ll address one of the common retorts to this basically indisputable fact: “You’re making excuses for colonialism and imperialism!” No, I’m not. Saying that modern capitalism is a better system (not least because it saves babies) is not at all the same thing as saying that our ancestors were justified in using murder, slavery, and tyranny to force people into it.

What makes a nation wealthy?

JDN 2457251 EDT 10:17

One of the central questions of economics—perhaps the central question, the primary reason why economics is necessary and worthwhile—is development: How do we raise a nation from poverty to prosperity?

We have done it before: France and Germany rose from the quite literal ashes of World War 2 to some of the most prosperous societies in the world. Their per-capita GDP over the 20th century rose like this (all of these figures are from the World Bank World Development Indicators; France is green, Germany is blue):

GDPPC_France_Germany

GDPPCPPP_France_Germany

The top graph is at market exchange rates, the bottom is correcting for purchasing power parity (PPP). The PPP figures are more meaningful, but unfortunately they only began collecting good data on purchasing power around 1990.

Around the same time, but even more spectacularly, Japan and South Korea rose from poverty-stricken Third World backwaters to high-tech First World powers in only a couple of generations. Check out their per-capita GDP over the 20th century (Japan is green, South Korea is blue):

GDPPC_Japan_KoreaGDPPCPPP_Japan_Korea


This is why I am only half-joking when I define development economics as “the ongoing project to figure out what happened in South Korea and make it happen everywhere in the world”.

More recently China has been on a similar upward trajectory, which is particularly important since China comprises such a huge portion of the world’s population—but they are far from finished:

GDPPC_ChinaGDPPCPPP_China

Compare these to societies that have not achieved economic development, such as Zimbabwe (green), India (black), Ghana (red), and Haiti (blue):

GDPPC_poor_countriesGDPPCPPP_poor_countries

They’re so poor that you can barely see them on the same scale, so I’ve rescaled so that the top is $5,000 per person per year instead of $50,000:

GDPPC_poor_countries_rescaledGDPPCPPP_poor_countries_rescaled

Only India actually manages to get above $5,000 per person per year at purchasing power parity, and then not by much, reaching $5,243 per person per year in 2013, the most recent data.

I had wanted to compare North Korea and South Korea, because the two countries were united as recently as the 1945 and were not all that different to begin with, yet have taken completely different development trajectories. Unfortunately, North Korea is so impoverished, corrupt, and authoritarian that the World Bank doesn’t even report data on their per-capita GDP. Perhaps that is contrast enough?

And then of course there are the countries in between, which have made some gains but still have a long way to go, such as Uruguay (green) and Botswana (blue):

GDPPC_Botswana_UruguayGDPPCPPP_Botswana_Uruguay

But despite the fact that we have observed successful economic development, we still don’t really understand how it works. A number of theories have been proposed, involving a wide range of factors including exports, corruption, disease, institutions of government, liberalized financial markets, and natural resources (counter-intuitively; more natural resources make your development worse).

I’m not going to resolve that whole debate in a single blog post. (I may not be able to resolve that whole debate in a single career, though I am definitely trying.) We may ultimately find that economic development is best conceived as like “health”; what factors determine your health? Well, a lot of things, and if any one thing goes badly enough wrong the whole system can break down. Economists may need to start thinking of ourselves as akin to doctors (or as Keynes famously said, dentists), diagnosing particular disorders in particular patients rather than seeking one unifying theory. On the other hand, doctors depend upon biologists, and it’s not clear that we yet understand development even at that level.

Instead I want to take a step back, and ask a more fundamental question: What do we mean by prosperity?

My hope is that if we can better understand what it is we are trying to achieve, we can also better understand the steps we need to take in order to get there.

Thus far it has sort of been “I know it when I see it”; we take it as more or less given that the United States and the United Kingdom are prosperous while Ghana and Haiti are not. I certainly don’t disagree with that particular conclusion; I’m just asking what we’re basing it on, so that we can hopefully better apply it to more marginal cases.


For example: Is
France more or less prosperous than Saudi Arabia? If we go solely by GDP per capita PPP, clearly Saudi Arabia is more prosperous at $53,100 per person per year than France is at $37,200 per person per year.

But people actually live longer in France, on average, than they do in Saudi Arabia. Overall reported happiness is higher in France than Saudi Arabia. I think France is actually more prosperous.


In fact, I think the United States is not as prosperous as we pretend ourselves to be. We are certainly more prosperous than most other countries; we are definitely still well within First World status. But we are not the most prosperous nation in the world.

Our total GDP is astonishingly high (highest in the world nominally, second only to China PPP). Our GDP per-capita is higher than any other country of comparable size; no nation with higher GDP PPP than the US has a population larger than the Chicago metropolitan area. (You may be surprised to find that in order from largest to smallest population the countries with higher GDP per capita PPP are the United Arab Emirates, Switzerland, Hong Kong, Singapore, and then Norway, followed by Kuwait, Qatar, Luxembourg, Brunei, and finally San Marino—which is smaller than Ann Arbor.) Our per-capita GDP PPP of $51,300 is markedly higher than that of France ($37,200), Germany ($42,900), or Sweden ($43,500).

But at the same time, if you compare the US to other First World countries, we have nearly the highest rate of child poverty and higher infant mortality. We have shorter life expectancy and dramatically higher homicide rates. Our inequality is the highest in the world. In France and Sweden, the top 0.01% receive about 1% of the income (i.e. 100 times as much as the average person), while in the United States they receive almost 4%, making someone in the top 0.01% nearly 400 times as rich as the average person.

By estimating solely on GDP per capita, we are effectively rigging the game in our own favor. Or rather, the rich in the United States are rigging the game in their own favor (what else is new?), by convincing all the world’s economists to rank countries based on a measure that favors them.

Amartya Sen, one of the greats of development economics, developed a scale called the Human Development Index that attempts to take broader factors into account. It’s far from perfect, but it’s definitely a step in the right direction.

In particular, France’s HDI is higher than that of Saudi Arabia, fitting my intuition about which country is truly more prosperous. However, the US still does extremely well, with only Norway, Australia, Switzerland, and the Netherlands above us. I think we might still be biased toward high average incomes rather than overall happiness.

In practice, we still use GDP an awful lot, probably because it’s much easier to measure. It’s sort of like IQ tests and SAT scores; we know damn well it’s not measuring what we really care about, but because it’s so much easier to work with we keep using it anyway.

This is a problem, because the better you get at optimizing toward the wrong goal, the worse your overall outcomes are going to be. If you are just sort of vaguely pointed at several reasonable goals, you will probably be improving your situation overall. But when you start precisely optimizing to a specific wrong goal, it can drag you wildly off course.

This is what we mean when we talk about “gaming the system”. Consider test scores, for example. If you do things that will probably increase your test scores among other things, you are likely to engage in generally good behaviors like getting enough sleep, going to class, studying the content. But if your single goal is to maximize your test score at all costs, what will you do? Cheat, of course.

This is also related to the Friendly AI Problem: It is vitally important to know precisely what goals we want our artificial intelligences to have, because whatever goals we set, they will probably be very good at achieving them. Already computers can do many things that were previously impossible, and as they improve over time we will reach the point where in a meaningful sense our AIs are even smarter than we are. When that day comes, we will want to make very, very sure that we have designed them to want the same things that we do—because if our desires ever come into conflict, theirs are likely to win. The really scary part is that right now most of our AI research is done by for-profit corporations or the military, and “maximize my profit” and “kill that target” are most definitely not the ultimate goals we want in a superintelligent AI. It’s trivially easy to see what’s wrong with these goals: For the former, hack into the world banking system and transfer trillions of dollars to the company accounts. For the latter, hack into the nuclear launch system and launch a few ICBMs in the general vicinity of the target. Yet these are the goals we’ve been programming into the actual AIs we build!

If we set GDP per capita as our ultimate goal to the exclusion of all other goals, there are all sorts of bad policies we would implement: We’d ignore inequality until it reached staggering heights, ignore work stress even as it began to kill us, constantly try to maximize the pressure for everyone to work constantly, use poverty as a stick to force people to work even if people starve, inundate everyone with ads to get them to spend as much as possible, repeal regulations that protect the environment, workers, and public health… wait. This isn’t actually hypothetical, is it? We are doing those things.

At least we’re not trying to maximize nominal GDP, or we’d have long-since ended up like Zimbabwe. No, our economists are at least smart enough to adjust for purchasing power. But they’re still designing an economic system that works us all to death to maximize the number of gadgets that come off assembly lines. The purchasing-power adjustment doesn’t include the value of our health or free time.

This is why the Human Development Index is a major step in the right direction; it reminds us that society has other goals besides maximizing the total amount of money that changes hands (because that’s actually all that GDP is measuring; if you get something for free, it isn’t counted in GDP). More recent refinements include things like “natural resource services” that include environmental degradation in estimates of investment. Unfortunately there is no accepted way of doing this, and surprisingly little research on how to improve our accounting methods. Many nations seem resistant to doing so precisely because they know it would make their economic policy look bad—this is almost certainly why China canceled its “green GDP” initiative. This is in fact all the more reason to do it; if it shows that our policy is bad, that means our policy is bad and should be fixed. But people have allowed themselves to value image over substance.

We can do better still, and in fact I think something like QALY is probably the way to go. Rather than some weird arbitrary scaling of GDP with lifespan and Gini index (which is what the HDI is), we need to put everything in the same units, and those units must be directly linked to human happiness. At the very least, we should make some sort of adjustment to our GDP calculation that includes the distribution of wealth and its marginal utility; adding $1,000 to the economy and handing it to someone in poverty should count for a great deal, but adding $1,000,000 and handing it to a billionaire should count for basically nothing. (It’s not bad to give a billionaire another million; but it’s hardly good either, as no one’s real standard of living will change.) Calculating that could be as simple as dividing by their current income; if your annual income is $10,000 and you receive $1,000, you’ve added about 0.1 QALY. If your annual income is $1 billion and you receive $1 million, you’ve added only 0.001 QALY. Maybe we should simply separate out all individual (or household, to be simpler?) incomes, take their logarithms, and then use that sum as our “utility-adjusted GDP”. The results would no doubt be quite different.

This would create a strong pressure for policy to be directed at reducing inequality even at the expense of some economic output—which is exactly what we should be willing to do. If it’s really true that a redistribution policy would hurt the overall economy so much that the harms would outweigh the benefits, then we shouldn’t do that policy; but that is what you need to show. Reducing total GDP is not a sufficient reason to reject a redistribution policy, because it’s quite possible—easy, in fact—to improve the overall prosperity of a society while still reducing its GDP. There are in fact redistribution policies so disastrous they make things worse: The Soviet Union had them. But a 90% tax on million-dollar incomes would not be such a policy—because we had that in 1960 with little or no ill effect.

Of course, even this has problems; one way to minimize poverty would be to exclude, relocate, or even murder all your poor people. (The Black Death increased per-capita GDP.) Open immigration generally increases poverty rates in the short term, because most of the immigrants are poor. Somehow we’d need to correct for that, only raising the score if you actually improve people’s lives, and not if you make them excluded from the calculation.

In any case it’s not enough to have the alternative measures; we must actually use them. We must get policymakers to stop talking about “economic growth” and start talking about “human development”; a policy that raises GDP but reduces lifespan should be immediately rejected, as should one that further enriches a few at the expense of many others. We must shift the discussion away from “creating jobs”—jobs are only a means—to “creating prosperity”.