The July/August 2011 edition of the Atlantic has a great article by David Eagleman on the implications of advances in brain science on the way we approach crime (HT: Jeffrey Horn). Eagleman argues that these advances will require a reshaping of the criminal justice system to reflect the declining gap between whether actions can be attributed to biology and free will. Eagleman writes:

Technology will continue to improve, and as we grow better at measuring problems in the brain, the fault line will drift into the territory of people we currently hold fully accountable for their crimes. Problems that are now opaque will open up to examination by new techniques, and we may someday find that many types of bad behavior have a basic biological explanation—as has happened with schizophrenia, epilepsy, depression, and mania.

….

The crux of the problem is that it no longer makes sense to ask, “To what extent was it his biology, and to what extent was it him?,” because we now understand that there is no meaningful distinction between a person’s biology and his decision-making. They are inseparable.

Eagleman’s first response to this problem is to move away from blameworthiness. If you cannot distinguish the extent of volition (if it can even be argued to exist), it is hard to blame. As a result, Eagleman suggests that justice will need to become more forward-looking:

Instead of debating culpability, we should focus on what to do, moving forward, with an accused lawbreaker. I suggest that the legal system has to become forward-looking, primarily because it can no longer hope to do otherwise. As science complicates the question of culpability, our legal and social policy will need to shift toward a different set of questions: How is a person likely to behave in the future? Are criminal actions likely to be repeated? Can this person be helped toward pro-social behavior? How can incentives be realistically structured to deter crime?

…

Deeper biological insight into behavior will foster a better understanding of recidivism—and this offers a basis for empirically based sentencing. Some people will need to be taken off the streets for a longer time (even a lifetime), because their likelihood of reoffense is high; others, because of differences in neural constitution, are less likely to recidivate, and so can be released sooner.

While I agree the criminal justice system should ask what the law-breaker is likely to do in the future, it cannot desert the look in the rearview mirror. If you wish the justice system to offer an incentive to not commit crimes, it needs to act retrospectively or the threat of punishment will not be credible. If people have a biological propensity to commit a crime, you may need to make these incentives even stronger (Steven Pinker discusses this argument in The Blank Slate).

To make his forward-looking approach work, Eagleman suggests that the courts use statistically based sentencing. Statistical analysis can be used to find out which factors have the highest link to re-offending – and the evidence suggests that this is more accurate than leaving it to judges. I suggested this recently in response to the finding that the timing of lunch breaks in Israeli courts. Human judgement is a primary weakness in the criminal justice system. However, there will need to be a component of the algorithm that provides a certain, strong punishment that potential criminals can take into account.

While Eagleman’s article is thorough, there is one biological element missing from his analysis – the dynamic effects. Incarceration removes young men from the mating market during their mating prime. As the propensity to commit crime is heritable, the removal of criminals from the mating market will reduce the frequency of the genes associated with crime in the next generation. As Eagleman notes:

[I]f you are a carrier of a particular set of genes, the probability that you will commit a violent crime is four times as high as it would be if you lacked those genes. You’re three times as likely to commit robbery, five times as likely to commit aggravated assault, eight times as likely to be arrested for murder, and 13 times as likely to be arrested for a sexual offense. The overwhelming majority of prisoners carry these genes; 98.1 percent of death-row inmates do.

Instead of worrying about how to control the biologically impulsive, incarceration can simply cut their prevalence in the future.

Niall Ferguson has a slight Malthusian thread running through his book, Civilization: The West and the Rest (My review is here and some other Malthusian thoughts by Ferguson here). At one point, Ferguson touches on the mass emigration from England to the Americas. Ferguson writes:

[A]s England’s population accelerated in the late seventeenth century, overseas expansion played a vital role in propelling the country out of the Malthusian trap. Transatlantic trade brought an influx of new nutrients like potatoes and sugar – an acre of sugar cane yielded the same amount of energy as 12 acres of wheat – as well as plentiful cod and herring. Colonization allowed the emigration of surplus population. Over time, the effect was to raise productivity, incomes, nutrition and even height.

…

The Chinese and Japanese route – turning away from foreign trade and intensifying rice cultivation – meant that with population growth, incomes fell, and so did nutrition, height and productivity. When crops failed or their cultivation was disrupted, the results were catastrophic.

If people are the ultimate resource, emigration of surplus population would have negative consequences. A lower population will generate fewer ideas. However, the surplus population that emigrated to the Americas was not completely lost to Europe. Those people continued to innovate, and ideas could flow between Europe and its colonies.

Ferguson suggests that emigration is positive as it loosens the Malthusian bindings on the population. It may have been the case for a time. Yet, the English population more than tripled between 1740 and 1860 as the flow of English emigrating declined and fertility boomed. It was during this population boom that per person income finally reached the levels seen in the low population period after the black death. England exited the Malthusian state at a time that the Malthusian model would suggest it was least likely to occur.

With the cover of Niall Ferguson’s Civilization: The West and the Rest stating that it is “Now a Major Channel Four Series”, I should have foreseen the pace and structure of the book would be designed for entertainment and not presenting a painstakingly worked-through framework. Ferguson attributes the West’s ascension to six “killer apps”: competition, science, property rights, medicine, the consumer society and work ethic. As the West possessed all six of these apps, it was able to dominate the world for 500 years, with no other region possessing the full combination.

For the first three, Ferguson undertakes a pairwise comparison with other regions – the competition in Europe compared to China, the use of science in the West compared its suppression in the Muslim world and the introduction and broad spread of property rights in North America compared to the centralised and highly concentrated property ownership in South America. While each of these comparisons provides a strong argument about why these features are important, it sometimes leaves open the question of how this comparison would apply to other countries.

Take the explanation for property rights. Ferguson attributes the difference in property rights in North and South America to differences in the way the colonial powers allocated land. In the North, almost any new immigrant could eventually be a property owner and the institutions introduced supported the productive use of this land. In South America, a few people monopolised the land available, with most of the population effectively serfs. This comparison works well, but why did many other British colonies, such as those in Asia and Africa not have the same benefit. Ferguson may have a simple explanation, but I would like to hear it (My guess would relate to prevalence of indigenous people, one of the factors in the North-South America divide. For the United States in 1825, less than 4 per cent of the population was indigenous, allowing land to be freely allocated to new immigrants).

Ferguson does come to Africa in his discussion of medicine. However, this is where the television series drivers seem to have taken over. While Ferguson suggests the West introduced new medicines to Africa, there is little discussion in how this aided the West’s advantage. Instead, much of the discussion focuses on eugenics and the use of African troops in War. Interesting topics, yes, but the discussion I was expecting was missing. If anything, medicine’s introduction appears to be a benefit, unless you consider that there may be Malthusian consequences to higher population.

My usual critique of these kinds of books is that they spend too much time considering the incentives and actions of States and not enough of the people within them. On this, Ferguson comes closer to examining the incentives and actions of people than many other grand histories (such as Morris’s Why the West Rules … For Now), but he does not weave this fully into his narrative. For example, in his discussion of competition, he notes the competition between states in Europe that is absent in China. He then notes the competition within European states, such as the city versus the crown and the professions against each other. There is competition at all levels. However, he does not match this with discussion of what competition occurred between people in Chinese cities. Similarly, the Ottoman Empire may have suppressed science at the State level, but why were Muslim entrepreneurs not engaging in innovation to compete in commerce?

I found the most interesting topic to be the last – Ferguson’s discussion of religion. Ferguson argues that the work ethic in the West largely reflected the spread of Protestantism. This topic allows Ferguson to discuss whether the West will decline. As Ferguson notes, religion is declining in Europe, as “4 per cent of Norwegians and Swedes and 8 per cent of French and Germans attend a church service at least once a week, compared with 36 per cent of Americans, 44 per cent of Indians, 48 per cent of Brazilians and 78 per cent of sub-Saharan Africans.” While the American-European comparison is Ferguson’s main point, the sub-Saharan African figure stands out. Ferguson also talks of the rise of Christianity in China. However, having noted these trends, he also points out that the focus of religion in the United States has changed from one of saving and service to one of consumption. His discussion of the topic left me confused about how he saw these trends playing out. Are these changes in religious trends driving growth? It also highlights the usual correlation-causation question. Does someone work harder because they are a protestant or are they a protestant as it appeals to hard-working people? Or is there another relevant factor?

Ferguson does not convert these observations into bold predictions. He spends some time noting the complexity of global political systems, with small changes possibly leading to sudden, discontinuous changes. While the decline of empires may seem slow and obvious in retrospect, the fall is often sudden and unforeseen. As Ferguson writes:

It is historians who retrospectively portray the process of dissolution as slow-acting, with multiple over-determining causes. Rather, civilizations behave like all complex adaptive systems. They function in apparent equilibrium for some unknowable period. And then, quite abruptly, they collapse. To return to the terminology of Thomas Cole, the painter of The Course of Empire, the shift from consummation to destruction and then to desolation is not cyclical. It is sudden. A more appropriate visual representation of the way complex systems collapse may be the old poster, once so popular in thousands of college dorm rooms, of a runaway steam train that has crashed through the wall of a Victorian railway terminus and hit the street below nose first. A defective brake or a sleeping driver can be all it takes to go over the edge of chaos.

The sum of these parts makes for an interesting book. However, it is one to be read for entertainment and some interesting ideas. Those looking for a grand history of everything will be disappointed.

Not long after my recent post on the heritability of political views, Chris Mooney of The Intersection has posted on another article (with follow-up by Razib at Gene Expression) supporting the well-established finding that political views are heritable. The research found evidence for linkage between political beliefs and genes.

I’ll post in more detail on the article at another time (I’ve sat on it for a few months now, so another couple won’t matter), but some of the discussion is interesting. How do genetic influences flow through to political beliefs, particularly when what we consider to be conservative or liberal varies through time? As Razib writes:

The disposition toward conservatism and liberalism does not manifest in absolute tendencies, but attitudes and actions comprehensible only against a reference which allows for one’s own bias to come to the fore. This is why heritabilities of being conservative and liberal can remain the same over time and across cultures, even though conservative and liberal can mean very different things in different contexts.

We are observing the manifestation of personality in varied environments. It is not support for civil unions that will be found to have a consistent genetic basis, but rather the openness or agreeableness that might lead you to support or oppose it in certain environments.

It is for that reason that only yesterday I was writing how I should re-frame my discussion of the heritability of political attitudes in terms of intelligence and the big-five personality traits. Those personality traits line up fairly consistently with the conservative-liberal divide. However, across different times and places, the link between personality and specific issues is much looser. There will a pile of studies over the next few years finding heritability of a host of traits and beliefs, together with possible genetic associations. While each might seem unique, many of them will be manifestations of the same personality traits.

In Geoffrey Miller’s Spent: Sex, Evolution, and Consumer Behavior (earlier posts on his book here, here and here – this is the last one for now), Miller discusses how there might be a move away from a consumerist culture. To do this, there is a need to develop and maintain social norms that could act as an alternative to the typical displays of wealth. For example, in a religious community, signalling could be through time and resources given to the church.

However, Miller stated that there is a major legal obstacle to establishing these norms. The obstacle is that the laws about property ownership and rental do not allow discrimination. Despite the good intentions, Miller considers that “they have toxic side effects on the ability of voluntarily organized communities to create the physical, social, and moral environments that their members want.”

There is no shortage of literature on the effects of diversity on trust and cooperation within communities. Miller notes some of Robert Putnam’s work:

For example, the political scientist Robert Putnam has found that American communities with higher levels of ethnic diversity tend to have lower levels of “social capital” – trust, altruism, cohesion, and sense of community. He and his colleagues analyzed data from thirty thousand people across forty-one U.S. communities, and found that people who live in communities with higher ethnic diversity (meaning, in the United States, more equal mixtures of black, Hispanic, white, and Asian citizens) tend to have lower:

• trust across ethnic groups
• trust within their own ethnic group
• community solidarity and cohesion
• community cooperation
• sense of political empowerment
• confidence in local government and leaders
• voter registration rates
• charity and volunteering
• investment in common goods
• interest in maintaining community facilities
• rates of carpooling
• numbers of friends
• perceived quality of life
• general happiness

These effects remained substantial even after controlling for each individual’s age, sex, education, ethnicity, income, and language, and for each community’s poverty rate, income inequality, crime rate, population density, mobility, and average education.

As communities cannot group on norms, Miller states that communities group based on income.  Wealth becomes the measure of status and competition between individuals in the community is then dependent on displays of wealth. He states that “if the local majority cannot impose some distinctive social norms on our forms of trait signaling, conspicuous consumption will remain the only game in town.” You are limited to choosing your neighbours through the use of economic stratification:

Sadly, it has become almost impossible now for like-minded people to arrange to live together in a small community with cohesive social norms. Real norms can be sustained effectively only by selecting who moves in, by praising or punishing those who uphold or violate norms as residents, and by expelling those who repeatedly violate the norms. These are the requirements to sustain the type of cooperation called network reciprocity, in which cooperators form local “network clusters” (communities) in which they help one another.

I am not confident that if communities could discriminate and assort as they see fit that wealth would not be a major cause of assortment. Still, assuming that these laws are as much of a barrier as Miller suggests (I am not particularly familiar with United States discrimination laws), there would almost certainly be some groups that wish to assort on certain criteria. And why not let them? If it builds community trust and cooperation, that is a good thing. I am sure that some communities would form on bases that are abhorrent to others, but you don’t have to live there.

For most of Geoffrey Miller’s Spent: Sex, Evolution, and Consumer Behavior (earlier posts here and here), Miller treats the genetic influences on human preferences as relatively static over human history. However, in his discussion of the big-five personality trait of conscientiousness, Miller suggests that high conscientiousness was only selected for after the Neolithic Revolution:

In several respects, conscientiousness is an unusual personality trait. Because hunter-gatherer life did not require as much planning and memory for debts and duties as life in larger-scale societies with more complex divisions of labor, conscientiousness may have evolved to higher average levels only recently, and perhaps to a greater degree in some populations than others. Only with the rise of activities like agriculture and animal herding would our ancestors have needed the sort of anxious obsessiveness and future-mindedness that characterize the highly conscientious. Only in the past ten thousand years did our ancestors prosper by continually asking themselves: Have I plowed enough yet? Did I sow the seeds early enough? Is one of the lambs missing? Did my cousin pay me for those olives? Am I teaching my children the skills they will need in twenty years? Thus were born the sleepless predawn ruminations of the middle-aged conscientious.

Economically, conscientiousness is a positive trait (both individually and in the aggregate). While I would argue that other traits would have also faced selection pressures since the Neolithic Revolution, it is probably easier to build a case for conscientiousness evolving in an economically useful manner than for the other big-five traits.

Miller couched most of his discussion in Spent in terms of the big-five (openness, conscientiousness, agreeableness, stability and extraversion) plus general intelligence (the central six as he calls them). Rob Brooks did similarly in Sex, Genes & Rock ‘n’ Roll. It’s probably not a bad habit to get into, as Miller suggests most of the studies about the heritability of preferences (such as in my recent post on the heritability of political views) are simply reflections of the central-six. In their favour, the central-six are near statistically independent, apart from a slight correlation between openness and intelligence, and have survived in various forms through several decades of psychological research.

As for the trait I often talk about, time preference or patience, I expect that this is a combination of intelligence and conscientiousness.

Geoffrey Miller’s main thesis in Spent: Sex, Evolution and Consumer Behavior is that the conspicuous consumption we use to signal traits such as intelligence, agreeableness or conscientiousness is unnecessarily indirect. Instead, we should use our evolved abilities to show these characteristics through humour, communication and interaction with others. Miller summarises his position as follows:

Consumerist capitalism is largely an exercise in gilding the lily. We take wondrously adaptive capacities for human self-display – language, intelligence, kindness, creativity, and beauty – and then forget how to use them in making friends, attracting mates, and gaining prestige. Instead we rely on goods and services acquired through education, work, and consumption to advertise our personal traits to others. These costly signals are mostly redundant or misleading, so others usually ignore them. They prefer to judge us through natural face-to-face interaction. We think our gilding dazzles them, though we ignore their own gilding when choosing our own friends and mates.

I am sympathetic to Miller’s general argument. A few minutes of face-to-face communication can undo many signals, such as our choice of clothing or car. However, status, wealth and power are still qualities that matter to a mate. Given two mates of equal genetic value, the one with the higher resources or status would be expected to be better able to provide for the child. Through human history, parental wealth has had a strong correlation with child mortality (possibly only breaking down in developing countries in recent decades). There will be some rate of trade-off between resources and genetic quality, and we will want to signal our level of resources.

There are also limits to the accuracy of face-to-face assessment. While I may seem hard-working and conscientious, the fact I have worked to the top of my business is evidence of this. Can I fake conscientiousness through a few dates more easily than I can through a decade in a top company? Do I then need the BMW to show that I am actually successful in this company as opposed to being at the bottom of the pile?

Miller is optimistic that people can move away from the consumerist culture. Tongue-in-cheek, he suggests tattoos of our intelligence and big-five personality trait scores. While this may be a more accurate signal, for a signal to be useful we need to consider the recipient. Are they more aroused by the sight of my IQ score, my bank statement or the BMW acquired due to my intelligence and wealth? If they prefer the BMW signal, despite its lower accuracy, it would be a poor strategy on my part to deviate. As Miller notes:

There seems to be no easy shortcut through our person-perception systems. We have to feed them the kinds of social stimuli that they evolved to expect, and institutionally validated trait tattoos are not among those stimuli.

One thread of the book I appreciated is Miller’s argument that government should remove any barriers to checking out of consumer culture. In some ways, that is the appeal of the libertarian state – those who wish to check out can. While Miller has this freedom-supporting thread, he is not averse to Pigovian taxes on a raft of products. He writes:

All negative externalities are, by definition, encroachments on other people’s lives and property. So, even hard-core libertarians who believe that governments should do nothing more than protect people from such encroachments should be willing to accept a consumption tax specifically designed to counteract such encroachments. From this viewpoint, the consumption tax is not paternalistic meddling. Rather, it is a classical “Pigovian tax” designed to correct the negative externalities of market activity. … From that perspective, it seems reasonable that governments should impose consumption taxes designed to neutralize each product type’s externalities. In other words, we should be free to choose what we buy and how we live, as long as we pay the fair price for every harm we do to others in the process.

If we are going to raise tax revenue, Pigovian taxes are one of the more efficient ways to do it. However, Miller spots my number one concern:

Skeptics might object that to set appropriate product-specific consumption tax rates would require a vast new government bureaucracy. We would need thousands of economists, statisticians, actuaries, and psychologists to measure all the externalities, risks, and costs of every product class. That is true, but that is precisely what we need: good solid data about the true social and environmental costs of the goods and services we buy. If we don’t collect and analyze such data, all arguments about the social and environmental effects of different policies are just blather. They can’t be evidence-based if there is no evidence.

Miller’s view of a product-by-product assessment would seem to offer massive opportunity for companies to lobby for different taxes on competitor’s products as theirs has a longer-life or is more environmentally friendly. And I’m not sure it is required. As an alternative, taxes at the source, such as a carbon tax, would allow the market to allocate the carbon price across products. To address the short life-span of products, you make people pay the costs of their disposal. The bureaucracy could be smaller than it is.

Some of Miller’s other proposals, such as subsidies for positive externalities like fitting airbags to cars, might also be better addressed by looking at the incentives.  If we put more of the burden of health care of individuals, this increases their incentive to act safely. They can choose their own balance between airbags and speed – or possibly an insurance policy that gives them a discount because they have airbags.

Miller ends the book with a series of exercise for the reader. You can go through a check-list of the experiences of our paleolithic ancestors, assess what is the purposes of your consumption and consider alternative signalling techniques. It is a useful set of exercises and highlights what is the most useful message of the book – as you go to make each purchase, consider what you are intending to signal by it and whether there is a more effective way to send that message. Are you simply sending the same signal as everyone else? In Miller’s words:

You anticipate the minor mall adventure: the hunt for the right retail environment playing cohort-appropriate nostalgic pop, the perky submissiveness of sales staff, the quest for the virgin product, the self-restraint you show in resisting frivolous upgrades and accessories, the universe’s warm hug of validation when the debit card machine says “Approved,” and the masterly fulfillment of getting it home, turned on, and doing one’s bidding. The problem is, you’ve experienced all this hundreds of times before with other products, and millions of other people will experience it with the same product. The retail adventure seems unique in prospect but generic in retrospect. In a week, it won’t be worth talking about.

If your intention was to send a signal with this product, forget it. But if it is useful, that’s another thing.

* Follow up posts on Spent can be found here, here and here.

Last week I came across a 2007 article by Niall Ferguson on increasing food prices and the potential for future shortages.  Leaving aside Ferguson’s predictions of the return of Malthusian misery, he makes an important and often forgotten point about what Malthus described in his An Essay on the Principle of Population. Ferguson writes:

Malthus concluded from this inexorable divergence between population and food supply that there must be “a strong and constantly operating check on population”.

This would take two forms: “misery” (famines and epidemics) and “vice”, by which he meant not only alcohol abuse but also contraception and abortion (he was, after all, an ordained Anglican minister).

“The vices of mankind are active and able ministers of depopulation,” wrote Malthus in an especially doleful passage of the first edition of his Essay. “They are the precursors in the great army of destruction; and often finish the dreadful work themselves.

“But should they fail in this war of extermination, sickly seasons, epidemics, pestilence, and plague advance in terrific array, and sweep off their thousands and tens of thousands. Should success be still incomplete, gigantic inevitable famine stalks in the rear, and with one mighty blow levels the population with the food of the world.”

……

[V]ice and misery have been operating just as Malthus foresaw to prevent the human population from exploding geometrically.

On the one hand, contraception and abortion have been employed to reduce family sizes. On the other hand, wars, epidemics, disasters and famines have significantly increased mortality.

Together, vice and misery have ensured that the global population has grown at an arithmetic rather than a geometric rate. Indeed, they’ve managed to reduce the rate of population growth from 2.2 per cent per annum in the early Sixties to around 1.1 per cent today.

While I am not sure that Ferguson’s statement on increased mortality is correct, developed countries have experienced a preventative fertility check in the form of active birth control. What would the developed world look like without that check? I expect population advocates such as Julian Simon would argue that we’d be richer, Malthusians the opposite.

In A Farewell to Alms, Gregory Clark made a similar point where he noted that higher living standards in many Pacific islands (relative to pre-Industrial Revolution England) was due to practices such as infanticide. When considering the Malthusian model, we should note both preventative and positive fertility checks.

The question that always interests me about preventative checks is how long the “vice” restrictions on population can operate. As the parents of the next generation are those immune to the vices, will the vices provide only a temporary check?

As I indicated in my recent post on Rob Brooks’s Sex, Genes and Rock ‘n’ Roll: How Evolution Has Shaped the Modern World, Brooks devotes some time to the issue of obesity. Rob has also blogged about obesity and published a paper with Steve Simpson and David Raubenheimer on it (although the book covers more ground).

First, why is obesity an evolutionary problem? In his book, Brooks set out why:

Some researchers use the fact that the obesity crisis emerged so recently as a reason to reject or ignore evolutionary or biological explanations for the crisis. After all, they argue, evolution takes thousands of generations. While they are certainly correct that we are not evolving to become fatter, obesity certainly has deep evolutionary roots among its causes. …

The combinations of genes that we inherited from our ancestors are adapted to the environments where those ancestors lived and bred, not the environments we inhabit today.

For most of our evolutionary history, humans ate a diet high in protein and fat, with some complex carbohydrates. With the neolithic revolution, some populations increased the proportion of their diet that consisted of carbohydrates. Over the last 50 or so years, the level of simple carbohydrates in diets has soared. Humans are not adapted to this modern diet and populations that have only very recently been exposed to this modern diet are more likely to face problems. This can be seen in the high rates of obesity on many Pacific islands or the high rates of diabetes and alcoholism among indigenous populations.

One of the arguments as to why the modern diet poses a problem is the protein leverage hypothesis. The basic idea is that humans have a stronger propensity to regulate protein intake than non-protein calories. As humans have a basic daily protein need – we eat until we satisfy our protein requirements. If the food we are eating has low protein content, we need to eat more before hitting that satiation point. These extra calories are what make us obese.

Brooks and his paper co-authors then took this question into the modern supermarket and looked at the prices of protein and carbohydrates. In his book, Brook’s summarises their findings:

I did a quick assessment of the costs of 111 common foods in my local supermarket and takeaway outlets. I was amazed that every megajoule (1000 kilojoules or 239 calories) of energy from protein adds US$3.26 to the average price of a food, but every megajoule of carbohydrate actually reduces the cost of food by 38 cents. …. Because sugars and starches are cheaper relative to protein than at any other time in human history, economic costs are likely to bias the foods we buy and eat toward energy-rich yet protein-poor diets. Within industrialised societies this effect is likely to be most extreme for poor people who have access to a wide range of foods but who are constrained in which foods they can afford to buy.

This led them to estimate that to cut kilojoule intake by 1,600 kilojoules (the estimated jump in calorie intake since the early 1970s) would require a subsidy of US$0.72 per person per day. This is around $262 per obese person per year, or around one-fifth of the estimated annual medical spending due to obesity.

It provides a case for government action, with the benefits well excess of the cost. Brooks puts it as follows:

One possibility is to subsidise high-protein foods such as lentils, lean meat and fish. Another is to reduce subsidies or tariff protection on sugar and cereal staples. An alternative to the politically perilous business of intervening in commodities markets is to tax products that clearly generate a large part of the public health burden. Reductions in carbohydrate intake might more effectively be achieved by raising the price of carbohydrate energy than by lowering the price of protein. Products like soft drinks, cordials, fried potato products and ice cream constitute a large proportion of the energy intake of adults and children at risk of obesity but contain little or no protein. Special taxes on cheap carbohydrates could well prove to be particularly effective.

Getting rid of subsidies and tariffs is an excellent idea, but I am not sure this is a one-way street for obesity reduction. Sugar quotas in the United States raise the price of sugar. Or take high-fructose corn syrup. Corn prices are artificially inflated by the ridiculous ethanol related subsidies in the United States. Would a truly unsubsidised, free market in corn raise or lower the price of corn syrup? I’m not sure, although that is one experiment I would like to see.

On the subsidisation of high protein foods, I am not sure whether this would succeed. Assuming the subsidisation occurred at the point of sale, we would see an increase in demand for these products and some substitution from carbohydrate heavy foods to these subsidised foods. However, we would also see an income effect, whereby the person could use the extra income freed up by the lower price of protein to buy more ice cream. We might also see underlying protein prices increase, with increased demand leading to much of the subsidy going to the fixed factor – the primary producer of the protein.

I’d be more optimistic about the effect of a tax on high-sugar products. There is reasonable evidence that soft-drinks and the like have a high price elasticity (demand is responsive to changes in price). However, there is also likely to be an income effect, whereby reduced income caused by the higher price of sugar might cut protein consumption. I would not expect the reduction in protein purchases due to reduced income to be larger than the incentive to substitute protein for sugars, but we should consider it.  This is particularly the case where obesity is most concentrated in the low socio-economic income groups.

A good step would be to test this by running some randomised trials (if they haven’t already been done) to see if the tax converts into reduced obesity. The evidence on food labelling and calorie disclosure is that it is ineffective, while there is a long history of sin taxes successfully reducing “sinful” consumption. However, I’m wary of these sorts of ideas as there are always unintended consequences. Sin taxes hit a wide number of people who are using the product sensibly. I’d like to see an estimate of the cost of their loss of enjoyment. Even among those who are obese, a substantial part of their life enjoyment might come from eating high-sugar foods. Perhaps they have decided it is worth the cost of obesity (and if you consider that they should not be allowed to impose the costs of their decision on the health system – don’t let them).

Thankfully, I’d be reasonably immune from these taxes as I like to stick to the edges of the supermarket. I’d encourage anyone to do this. However, this makes me even more reluctant to support a sugar tax. One should be wary of advocating intrusive actions when the intrusion is not on yourself.

I’ve just read Geoffrey Miller’s Spent, which I enjoyed. There are many interesting threads to the book, which I’ll blog about over the coming weeks.

In one of the earlier chapters, Miller discusses Maslow’s hierarchy of needs. The hierarchy, from the base to the top, consists of physiological, safety, love, esteem and self-actualisation needs. It is only on satisfaction of the first four needs that one will focus on self actualisation, which includes (among other things) morality, creativity and discovery.

Maslow’s hierarchy is often a framing point for discussions about development, concern for the environment and consumerism. The problem is, however, that it often doesn’t fit human behaviour. Miller puts this problem nicely:

It does not “cut nature at the joints” in terms of the key selection pressures that shaped human behavior: survival and reproduction. Survival includes most of Maslow’s physiological needs (breathing, eating), but also some of the more concrete safety needs (avoiding harm from predators, parasites, sexual rivals, and hostile tribes), social needs (building relations with family, friends, and mates who can help feed, protect, and heal you under adverse conditions), cognitive needs (to learn about survival-increasing opportunities and survival-reducing dangers), and even aesthetic needs (to find a propitious landscape for one’s clan to live in, to make weapons that are serviceably symmetric, strong, and sharp). Reproductive challenges, including finding high-quality sexual partners and raising high-quality offspring, encompass one of the key physiological needs (having sex) and most of the other social, esteem, cognitive, aesthetic, and self-actualization needs.

He then points out the more serious shortcoming:

[A] branch of evolutionary theory called “life history theory” points out that there are often tough trade-offs between these survival and reproductive priorities. The lower-level needs do not always take priority. For example, male elephant seals will often starve to death during a breeding season while guarding their harems. If elephant seals could talk, … they might explain that they were giving up a physiological need (to eat) for three higher needs: a social need (to feel intimacy and belonging with each of many females), an aesthetic need (to be surrounded by beautiful—that is, fine, fit, fat, fertile—females), and a self-actualization need (to be the best elephant seal one can be, as demonstrated through biting, mauling, bloodying, and excluding all male sexual rivals from one’s beach-front harem). But these last three Maslovian needs can actually be reduced to reproductive benefits. Natural selection crafted social, aesthetic, and self-actualization motivations because they yielded higher reproductive success over thousands of generations of elephant seal evolution. Male elephant seals who were “slackers,” content to fulfill their survival and safety needs without conflict, would have avoided the bloody beach sites where more ambitious “status seekers” fought, copulated, starved, and died. The slacker seals may have been perfectly happy, and might have even turned vegan and ate plankton, but they did not leave any descendants to inherit their easygoing temperaments. Only the male seals that were willing to compete for dominance, status, and harems, even at the cost of their own lives, sired any offspring.

There is no shortage of people (men) that are willing to significantly risk safety or forgo basic physical needs if they are deprived of reproductive opportunities.