If the link to this post from my earlier e-mail this morning didn’t work, this should (you might have to cut and paste the URL into your browser):
You can read the new post by The Melbourne Urbanist, Does urban sprawl really make us fat, at the new site at Crikey.
I know people who have the option of driving but instead take the train so they can improve their physical fitness. It takes longer than driving, but since they’re going to work anyway, walking to the station is an easy way to exercise. It makes good sense; I’ve walked or cycled to work at various times for the same reason.
However it’s one thing to make a private choice to use public transport in order to exercise – it’s another thing altogether to elevate the war on obesity and other health issues, as a matter of public policy, to the status of a key goal of the transport system. That’s what organisations like the Planning Institute and the National Transport Commission propose, but it’s not self-evident to me that it’s a good idea. It’s worth thinking about it further.
There’s a paradox here. The very point of public transport is to extend personal mobility. At the end of the nineteenth century when everyone other than the very wealthy walked, the arrival of trams and trains greatly enriched people’s lives by overcoming the limitations of walking. Now they could travel further to better jobs or better houses, take the family to the beach on Sunday, or visit friends and relatives in more distant suburbs. The whole point of public transport was to travel faster than walking so people could travel further in the same time.
The panoply of exercise-related issues like obesity are not a transport problem, they’re a social problem. They’re a result of eating more and of expending less effort in all aspects of life, not just in the way we travel. It’s true we are much more likely today to drive than walk, cycle or use public transport, but the avoidance of effort is true of almost everything we do.
Most of us work in jobs that don’t involve anything even remotely like the level of physical effort expended by the average worker of a few generations ago. If we did, Occ Health and Safety would have a fit. On the home front, we’ve had “labour saving” devices like refrigerators, stoves, washing machines and vacuum cleaners for generations. Television and home delivered newspapers mean we don’t even need to go out to get information and entertainment.
Consider the giant strides we’ve made in avoiding exertion over the last twenty years. Computers have eliminated the effort of going to the bank, the booking office, the travel agent or the bookshop. We blow leaves rather than rake them, we use power tools to drive nails and screws, we answer the phone without getting out of our seat, and we cook meals without having to prepare them. We control our air conditioners, central heating, TVs and sound systems with remotes. Climate control means our bodies don’t even consume much energy to keep warm – many children barely know what it means to shiver.
The decline of effort pervades all aspects of our lives, not just how we travel. For better or worse, it’s one of the ways we define progress. So transport – and that essentially means the car – is only one part of the health problem.
Lennert Veerman, Senior Research Fellow at Queensland University’s School of Population Health, points to a recent study which argues the main force driving the obesity pandemic is an increase in consumption. He says the 1970s was:
When the food supply started to change radically. The supply of refined carbohydrates and fat increased and more food was mass prepared rather than cooked at home. The era of easily available, cheap, tasty, highly promoted, energy-dense foods had begun. This view of the causes of the rise in obesity prevalence suggests the likely solutions lie in the area of the supply and promotion of food. And research supports that notion.
He says if governments are serious about tackling obesity their priority should be food. They should tax unhealthy food, limit advertising and restrict availability in schools. He also says healthy food should be subsidised. Read the rest of this entry »
The received wisdom is it costs much less to provide infrastructure for an inner suburban dwelling than for one in the outer suburbs. However, as I noted last time, we don’t know how big the difference is or even, for that matter, if it’s positive or negative – we simply lack reliable evidence.
There are reasons, however, to suspect the savings in infrastructure outlays associated with urban consolidation might be much less than is widely thought. It’s plausible that the popular claim of an $85,000 per dwelling saving could be well off the mark (note I’m only talking in this post about the capital cost of infrastructure, not the economic costs and benefits of a fringe vs central location).
From the time urban consolidation was first seriously put on the table in Australia as a policy option, a key premise was the availability of ‘spare’ infrastructure capacity in the inner city. This part of the city had previously supported larger working class and migrant populations, so there was ‘free’ infrastructure to be had in support of a restoration of earlier population levels.
There’s not much sense in assuming any capacity is free (it all has to be paid for) but looking from the perspective of 2011, there are reasons to question if there actually is any spare physical capacity left, at least in relation to some types of infrastructure.
A key reason is a lot of whatever spare infrastructure capacity existed has already been used up by gentrification. At the 2006 Census, there were 36,488 more residents in the inner city of Melbourne than there were in 1976 (and 76,422 more than when the inner city was at its lowest ebb in 1991). In fact of the 31 municipalities in metropolitan Melbourne, only the City of Moreland and the adjacent City of Darebin had significantly fewer residents in 2006 than in 1976 – Moreland had 14,585 fewer and Darebin 17,137 fewer. That is not a lot in the context of projections Melbourne will grow from a current population of four million to seven million by circa 2049.
Even where there are fewer residents today than in the past, they might still have a much larger “infrastructure footprint” than their predecessors. Modern households have many more resource-intensive devices like flat panel TVs, air conditioners, heaters, computers, spas, and so on, than their predecessors. They have more cars than former residents, so there’s less room for parking. They also have higher standards – the primary school that used to accommodate 300 kids in six or seven classrooms now has to build twelve to handle the same enrolment.
Moreover, households today are smaller on average, so they have fewer ‘economies of scale’ in resource consumption than earlier generations. Two households of three persons each use more gas for heating than they would if the same six residents shared a single dwelling. Gentrifying households are also wealthier on average than the sorts of households who used to live in the inner city and inner suburbs 30 to 40 years ago. On a per capita basis, wealthier households consume more of just about everything worth having. Again, that will require more infrastructure capacity.
Thus it’s possible infrastructure in some locations could be at or above capacity even with a much lower population than those places housed in the 1970s. Read the rest of this entry »
It’s often pointed out that residents of the inner city, on average, are less obese than residents of the outer suburbs. Since the inner city is denser, more walkable and has much better public transport access than any other part of the metropolitan area, the conclusion seems obvious to many – a key strategy to address obesity should be to encourage higher dwelling densities and better public transport in the suburbs, especially the newer, fringe areas.
The flaw in this thinking is it fails to observe that the inner city – defined roughly as the area within 5 km of the CBD – is a different world. Relative to the suburbs, the inner city has an emphatic over-representation of younger, well educated and affluent residents with fewer dependents. The proportion of the population made up of young singles is three times that of the metropolitan area as a whole and there are twice as many young couples without children.
These are the sorts of people who on average are slimmer because they’re younger, who are of an age where appearance is enormously important, and who are well educated enough to know about nutrition and eschew fast food. They can afford to buy high quality fruit and vegetables and pay for gym memberships. Because they’re more affluent, they have fewer children on average and hence less need for a car.
They live in smaller dwellings so they can be near the CBD and take advantage of its enormous and unparalleled concentration of high-paying professional jobs, its matchless endowment of cultural attractions and its huge and diverse range of social and entertainment opportunities. There’s no other concentration of activity within the metropolitan area that comes even close to the richness of what the inner city offers.
Because they live at higher density, driving is too hard for many trips – roads are congested and parking costs range from expensive to impossible. So residents often walk or use public transport instead. That’s O.K., because they happen to live in that transit-rich, small and unique geographical area where every train line and tram line in the entire metropolitan area – the result of 130 years of construction and at least one spectacular land boom – converges.
So population density and access to public transport are not the underlying forces driving this group’s superior average BMI. Rather, it’s a combination of the small but highly specialised group who can afford to live there, on the one hand, and the special characteristics of the area, particularly the presence of the CBD, on the other.
It’s pie in the sky to imagine the sheer scale and complexity of the highly specialised attributes offered by the inner city could be replicated in the suburbs – much less the outer suburbs – within the foreseeable future. The inner city is focussed on the CBD and in almost every city in the world, the number of jobs in the city centre is an order of magnitude larger than any suburban centre (Atlanta is possibly the sole exception). In Australia, the centre offers the cream of corporate jobs.
The importance of proximity to the CBD in explaining the special character of the inner city is demonstrated by the fact walking’s share of work trips plummets from 13% in the inner city to just 2% immediately one locates in the adjacent inner suburbs. This share is only marginally better than the outer suburbs.
Will building at higher densities and providing better public transport in the outer suburbs significantly lower the incidence of obesity? Not likely. Even if all outer suburban dwellings were townhouses, the incentive to walk is much lower if there’s no CBD, cultural precinct, river, beach, historic buildings, hundreds of cafes, and hundreds of thousands of jobs to walk to. Perhaps most importantly, the outer suburbs don’t have the constraints on driving and parking that often make walking or public transport a superior alternative in the inner city. Read the rest of this entry »
The link between the physical environment and health outcomes like obesity is fraught. The Victorian Legislative Council’s Environment and Planning References Committee should bear this in mind as it goes about its new inquiry into the contribution of environmental design to public health.
The Committee might want to start with the first chart in the accompanying exhibit, which comes from a recent issue of The Economist and purports to show that obesity has increased in the US in line with the increase in miles driven over the last 15 years. The chart is based on work done by researchers at the University of Illinois who found “a striking correlation between these two variables – but with a large time lag……This near-perfect correlation (99.6%) permits predictions about obesity rates”.
When you see a variable that follows a simple trend, almost any other trending variable will fit it: miles driven, my age, the Canadian population, total deaths, food prices, cumulative rainfall, whatever.
To demonstrate his point, Professor Wolfers prepared the second chart showing an even better correlation between changes in obesity over the period and changes in his age – he didn’t even need to resort to a time lag to get such a good fit! He acknowledges The Economist offered the customary caveat that correlation does not equal causation but this chart, he says, is so completely unconvincing as to warrant a different warning: “Not persuasive enough that you should bother reading this article” (in the interests of balance, here’s The Economist’s subsequent response to Professor Wolfer’s charge).
This exchange highlights a problem with much of the research that purports to show the physical environment — particularly density and/or public transport access — has a strong effect on health-related variables like obesity. There’s plenty of evidence of correlation but not much evidence of causation. There’s no doubt obesity is inversely related to both density and access to public transport, but if it turns out these aren’t the underlying drivers of obesity then the economic cost of misdirected policies could potentially be significant.
There are special reasons why it’s hard to establish causation when dealing with real life infrastructure projects and transport/land use programs. These British epidemiologists reviewed 77 international studies examining the effectiveness of policy interventions to reduce car use. They concluded the evidence base is weak, finding only 12 were methodologically strong – and they mainly involved relatively small-scale initiatives like providing better information about travel options or direct financial incentives to reduce driving (incidentally, only half of those 12 actually worked i.e. reduced car use). Read the rest of this entry »
I’ve said before that there isn’t one ‘Melbourne’ – there are multiple ‘Melbournes’. The home range of Melburnians is pretty restricted – the great bulk of their travel is made within a region defined by their home municipality and contiguous municipalities. Many suburbanites rarely visit the city centre, much less the other side of town.
This pattern of sub-regionalisation is illustrated by Melbourne’s three major universities. I posted on March 16th about the mode shares of work trips to these universities. To summarise, at the time of the 2006 Census, 41% of Melbourne University staff drove to work while over 80% of staff at Monash and La Trobe Universities commuted by car.
The accompanying charts look at something else – where university workers lived in 2006. They show a number of interesting things.
The first chart indicates that staff of these three universities don’t tend to live west of the Maribyrnong. The west has 17% of Melbourne’s population but houses only 8% of Melbourne University’s staff. The ring road provides good accessibility from La Trobe to the west but even so, only 3% of the university’s staff live there.
Second, Monash and La Trobe serve distinct regional markets, in the north and south (of the Yarra) respectively. Melbourne University has a more metropolitan ambit but it still has a sub-regional focus – its staff strongly favour the inner city and the inner northern suburbs.
Third, university staff like to live close to their employer. This is particularly evident with La Trobe, where 56% of staff reside within the four municipalities closest to the university i.e. Darebin, Banyule, Nillumbik and Whittlesea (see second chart). Read the rest of this entry »
Herald Sun journalist Andrew Bolt glosses easily over the potential negative health implications of the troubled Fukushima Dai-Ichi nuclear reactor in Japan. He says too much emphasis is given to the Chernobyl disaster because, contrary to received wisdom, he maintains only 65 deaths are associated with this accident. But there’s more to it than that.
These accounts (here and here) from Wiki indicate there are wildly varying claims about the number of deaths associated with the accident. The World Health Organisation estimated deaths at 4,000; Greenpeace at 200,000; and this Russian report, translated in 2007, says there were one million deaths, 170,000 of them in North America.
However estimates of deaths by the UN Scientific Committee on the Effects of Radiation are broadly consistent with Andrew Bolt’s claims. But what Bolt fails to mention, and the UN draws attention to, is the long run health implications of the accident.
For example, by 2005 there were 6,000 diagnosed cases of thyroid cancer among residents of Belarus, Ukraine and proximate parts of Russia, who were children at the time of the accident. According to the UN, it is most likely that a large fraction of these cancer cases are attributable to radioiodine intake (fortunately, thyroid cancer is usually treatable – the 30 year survival rate is 92% – but it’s a gruelling experience).
Now a new study has drawn attention to the cognitive risks of radiation exposure. Douglas Almond, a Columbia University Professor, wrote to the New York Times earlier this month pointing out that even low levels of radiation can have severe consequences for unborn children. He and his collaborators recently published a study of the effect of fallout from Chernobyl on Swedish children.
Sweden experienced radiation levels from Chernobyl that were so low they were considered safe. Almond’s team confirms that this presumption was mostly right. However they found that “Swedish students who were in utero during the accident experienced significantly lower cognitive functions, as reflected in performance on standardised tests in middle school, especially those tests that correspond best to IQ”. Read the rest of this entry »
Workers who commute to Melbourne University at Parkville are much more inclined to use public transport than their colleagues who work at suburban Monash or Latrobe universities. The chart shows that at the 2006 Census, 41% of Melbourne University workers reported they drove to work compared to 83% at Monash and 84% at Latrobe universities. Many more staff at Melbourne also walked and cycled – 24% compared to 6-7% at the other two institutions.
Melbourne University’s lower car use is explained by a few key factors. The main one is that it is located on the edge of the CBD where car use is limited by high levels of traffic congestion and expensive all-day parking charges. For many staff, driving would take too long, generate too much angst and be too expensive. If the value of driving is marginal, the decision to choose an alternative will be tipped by the high quality of public transport service available to Parkville workers. Although it’s not served directly by rail (none of these universities are), Melbourne University has easy access by multiple tram lines to the CBD and thence to the many radial train and tram lines linking to the larger metropolitan area. For many Melbourne University workers public transport would be a no-brainer.
Melbourne University’s high level of walking can largely be attributed to the relatively high residential densities in the nearby CBD and inner city environs. If transport is expensive in outlays and time, it makes sense for workers to live close to the university. In this case, living close to the university also means living close to the many activities and opportunities offered by the inner city.
The suburban setting of Monash and Latrobe provides a very different environment. Although these universities are not without their challenges, they generally experience less traffic congestion and enjoy cheaper parking than Melbourne University. Low suburban residential densities and large open space and industrial uses mean fewer staff can live within walking distance. The level of public transport service is actually pretty reasonable by prevailing standards (for example, see here) but obviously not as good as Melbourne University, which benefits greatly from its proximity to the CBD. Read the rest of this entry »
Some new research suggests they do!
One of the arguments against My School is that information on the performance of different schools will be interpreted incorrectly by the press, the public and parents.
The concerns usually relate to fears that schools will ‘teach to the test’; high socioeconomic status parents will abandon under-performing schools; or due regard will not be given to the special conditions that apply to some schools.
While I acknowledge there are risks with performance data, I’m suspicious of anyone who tells me that parents can’t be trusted – supposedly for both their own good and the good of their children – with full information about their child’s school.
I’ve written about My School before in the context of the ICSEA Index (here and here). With the revised My School web site going live on Friday, it’s timely to look at some recently published research on school league tables in Wales and The Netherlands (H/T Alex Tabarrok).
The research on Wales takes advantage of a ‘natural experiment’ – secondary school performance tables that have been published in both England and Wales since 1992 were abolished in Wales in 2001 but maintained in England. The research examines the effects over the subsequent years in both jurisdictions.
The University of Bristol researchers found there is “systematic, significant and robust evidence that abolishing school league tables markedly reduced school effectiveness in Wales”. They estimate the negative impact on schools is equivalent to increasing class size from 30 pupils to 38.
They also find that the negative effect is “concentrated in the schools in the lower 75% of the distribution of ability and poverty” and argue that the “results show that the policy reform in Wales reduced average performance and raised educational inequality”. Read the rest of this entry »
It’s commonly taken for granted that a disproportionately large number of fast food stores in an area is a key reason why the local population often has high rates of obesity.
The California Centre for Public Health Advocacy, for example, argues that “there is growing scientific evidence that what people eat—and their likelihood of being obese—is influenced by the food environment in which they live”.
More people are going to fast food restaurants where the food is high in calories and portions are large. Many respectable studies have shown a clear correlation between average body weight and eating out. According to one, growth in the number of restaurants accounts for as much as 65% of the rise in the percentage of Americans who are obese.
Various policies have been proposed to break the evident connection between fast food restaurants and obesity. These include proposals to limit the number of fast-food restaurants, ‘fat taxes’, limits on fast food advertising and mandatory calorie counts on menus.
But do fast food restaurants really cause obesity? As with many things, appearances may be deceiving. Correlation doesn’t mean causation.
This study, Are Restaurants Really Supersizing America?, by UC Berkeley researchers Michael Anderson and David Matsa, poses this question: “do more restaurants cause obesity or do preferences for greater food consumption lead to an increase in restaurant density?”. Read the rest of this entry »
As I’ve argued before (here) there are a number of reasons why buying food locally is probably the least sustainable basis on which to base your food buying preferences.
First, transport is only a small component of the total carbon emissions from agriculture.
Second, most food can’t be grown locally without resorting to potentially environmentally damaging practices like excessive application of fertiliser, irrigation or artificial heating of greenhouses.
Third, even where the local area is suitable for growing certain foods, it might not be the most environmentally efficient location for a particular food.
Fourth, producers in more distant locations might have superior farming practices to local growers. Fifth, the environmental and economic cost of moving people is higher than the cost of transporting their food.
Now Stephen Budiansky has assembled an array of interesting factoids in this NY Times oped, Math lessons for locavores, to show the folly of being a locavore. He’s a stylish writer so you might want to read the full article; otherwise here are a few key quotes:
- “Whether it’s grown in California or Maine, or whether it’s organic or conventional, about 5,000 calories of energy go into one pound of lettuce. Given how efficient trains and tractor-trailers are, shipping a head of lettuce across the country actually adds next to nothing to the total energy bill. Read the rest of this entry »
The editorial writer in The Age today reckons many teachers and parents will be underwhelmed by the Government’s new
$208 $258 million Education for Life promise. The writer bemoans the lost opportunity for the Government to advance some “big ideas”.
I agree that Education for Life won’t rattle the windows of most voters, but the objectives of the program are important and worthwhile. As explained by VECCI, it addresses the disengagement of many young people from the education system. This is a program that, if done well, might help to tackle the sorts of safety and security issues around trains that I discussed yesterday.
It’s a pity, though, that the Premier didn’t use the opportunity of the campaign launch to also pick up on the important message in the new report on teacher effectiveness released this week by Melbourne’s own Grattan Institute, Investing in our teachers, investing in our economy.
In the past I’ve wondered what the purpose of some of the Institute’s reports is, but not this one. Its message is clear and direct – improving teacher effectiveness is the single most important reform that could be put in place to improve educational outcomes.
The report makes three key points. Read the rest of this entry »
A new US study has found that there is a significant association between public transport use and reductions in Body Mass Index over time.
The researchers did an initial “before” telephone survey of residents living within one mile of a proposed new light rail line in Charlotte NC. They followed up with an “after” telephone survey 6-8 months after the new line opened.
There are some major methodological limitations with the study. Respondents self-reported their weight. The initial sample of 839 fell to 498 respondents in the follow-up phase. Only 26 respondents used the new line to commute on a daily basis.
Nevertheless, I have no difficulty with the proposition that those who choose to commute by transit are likely to be thinner than those who choose to drive to work. After all, transit requires the expenditure of more calories on walking and standing than driving does.
But in my view, the key issue is to what extent better health outcomes – and in this context specifically weight reduction – should shape transport policy. In order to look at that issue it is essential to understand what’s driving the “obesity epidemic” in Australia. Read the rest of this entry »
I have a modest idea for making our major cities more liveable that I’d like to offer to the Premiers and Opposition Leaders of Victoria, NSW and Queensland in the run up to their forthcoming State elections.
The idea could be named something like the Better Neighbours Initiative or it could as easily be titled Considerate Cities or Liveable Cities or something of that ilk. The idea starts with the recognition that living in close proximity within cities imposes stresses on human relations and demands strong remedial action.
Some of the risks associated with cities, like disease, respond to investment in physical infrastructure. But some don’t – they require behavioural approaches.
The main objective is to limit the stress that inconsiderate behaviour, like noise from “hot” cars or audio amplifiers, imposes on residents and neighbours. I’ll focus on noise here, but the ambit of the liveable cities idea could extend to other problems such as taming the speed and behaviour of cars in local streets and activity centres. Read the rest of this entry »
The map shows what residents call the “black hole” and this story in The Age gives the history of high school closures in the area:
“The troubled Moreland City College closed in 2004. Coburg High School shut its doors in 1993 and is now the site for a planned 510 apartments. Newlands High School, now part of the Pentridge Prison development, folded in 1993. Moreland High School taught its final class in 1991 and is now Kangan Batman TAFE”.
The Education Department says there isn’t sufficient demand to meet the minimum size requirements for a junior high school and that there are others nearby with adequate capacity to take Coburg children from year seven. The residents argue that these schools are either too far away or unsuitable.
There are two existing high schools within the circle, shown in grey on the map, but they are not full-service schools. One is Coburg Senior High (co-ed, year 10 upwards) and the other is Preston Girls College (girls 7-12 only). The obvious “new junior school” solution is to expand Coburg Senior High.
I’m not concerned with the reasonableness of either side’s case, but I am interested in the issue of how far teenagers should reasonably be expected to travel to school. I also think there’s some insight to be had here into the issue of whether or not there is spare infrastructure capacity in inner suburbs. Read the rest of this entry »
I’ve cautioned before about the dangers of physical determinism i.e. glibly assuming that the physical environment (or geography) is the driving force underlying human behaviour. Sometimes it is, sometimes it exacerbates another problem, but more often it’s the symptom rather than the cause.
So it was with interest that I noted a new study reported in The Age today that investigated if Melbourne and Sydney GPs who are co-located with pathology collection centres tend to order more tests than GPs who aren’t. I’ve had a look at the study, undertaken by the Melbourne University School of Population Health, in the latest issue of the Medical Journal of Australia.
The study defines co-location as where a GP and a pathology centre are located in the same premises. This group was compared with GPs located at least 50 metres from the nearest pathology centre.
The hypothesis that co-location might lead to a higher propensity to order pathology services seems plausible given, as the authors say, that many studies have shown how doctors’ contact with the pharmaceutical industry can influence their clinical decision-making: Read the rest of this entry »
This photograph, via Paul Romer, shows students in Guinea who go to the airport to study for exams because they don’t have electricity at home.
The BBC reports that petrol stations, airports and even spaces under security lamps outside upmarket homes have become pockets of learning, where determined students are to be found in large numbers.
Access to light is a serious problem due to the “deterioration of power supplies, which started in 2003 when the country’s economy went into freefall:
The national power company, Electricite de Guinee, provides light to consumers on a rotational basis of 12 hours a day – but even so, these schedules often prove erratic, with dozens of outages before dawn…..
Between 1999 and 2002, schools in Guinea had a modest pass rate of 30-35%. Since 2003, that has dropped to between 20 and 25%”. Read the rest of this entry »