Friday 29 June 2012

Rising cycling casualties: policy needs to catch up, and fast

We had new statistics on road casualties in 2011 at both national and London level yesterday, and in both cases the figures on cycling make for grim reading. The number of cyclists killed or seriously injured increased from 2010 levels by 15% nationally and by an even worse 22% in London. As the chart below shows, fatal or serious cycle casualties in London are down over the long term but up sharply in recent years.

Naturally people are interested in what this means for the rate of cycling casualties per trip or mile cycled. Some other DfT figures released yesterday indicate that miles cycled nationwide rose by only 2%, which implies a large increase in the casualty rate (see's number crunching). TfL will probably not release statistics on cycle trips in 2011 until their next Travel in London report (probably just after Christmas) but I don't think anyone seriously expects cycling to have grown more than 22% in a single year.

And anyway, even if I'm wrong and cycling levels were up by more than 22%, would that make such a large increase in the absolute number of casualties okay? To illustrate the point, say the number of trips cycled in London grew by 25% each year for five years and the number of cyclists killed or seriously injured by 20%. Going by TfL's figures for 2010 from this report and assuming everything else stayed the same, then by 2015 we'd have 1.5m cycling trips a day, a modal share of 6%, a lower cycling casualty rate BUT over 1,000 cyclists killed or seriously injured a year. Should that really be considered a success? 

Of course that's a slightly unrealistic scenario, but the point is that cycling casualties are rising at an alarming rate, in part because more and more people are choosing to cycle (for whatever reason). We all like to see cycling growing, but if it is not to result in truly horrific numbers of deaths and injuries then we need a complete transformation in cycling conditions in this city. 

Fortunately there is, on the face of it, a political consensus around this issue, as in the run-up to the 2012 mayoral election every major candidate endorsed the London Cycling Campaign's 'Go Dutch' manifesto, which entails dropping our current approach to road design and embracing the Dutch ethos, including high-quality segregated cycle lanes on busy main roads. So really there should be no debate about the general principle of what do do, just about the details of how to do it. I hope the forthcoming London Assembly transport committee inquiry into cycle safety adopts this approach.

Of course Transport for London and various individual politicians will say that it can't be done in London because we don't have the space on our roads. But I think these latest casualty figures show that we have no choice but to make the space. To turn the old slogan on its head, we haven't built the infrastructure but the cyclists are coming anway, and as a result they're getting killed or injured in greater and greater numbers. They have forced the issue, and policy has to catch up.

Tuesday 19 June 2012

Homeownership and growth in the great recession

There has been a bit of a discussion going round about the link between home ownership rates and national prosperity - see Marginal Revolution, Matt Yglesias and Melbourne Urbanist.

The upshot is that when you look at the data, home ownership rates seem at best uncorrelated with prosperity at national level and possibly even negatively correlated. Lots of poor countries have very high levels of home ownership while at the other end you've got countries like Switzerland and Germany, who seem to have got by pretty well with ownership rates of less than 50%.

Part of this pattern, in Europe at least, is explained by the fact that many post-Soviet countries simply handed over ownership of public housing to the occupiers en masse as part of their economic reforms in the 1990s, instantly creating very high rates of home ownership.

But another big part of the explanation is that wealthier countries are more urbanised, and higher rates of urbanisation mean lower rates of home ownership. Big, dense cities are great wealth creation machines, and higher-density housing is more likely to be rented than owned, partly for reasons of population transience and partly for reasons of efficiency - owning an apartment is a risky business because you are so affected by your fellow building occupants, so it often makes sense to let one landlord own the whole building and absorb all those inter-apartment externalities.

Lastly, Andrew Oswald has argued that higher rates of home ownership impede the labour market by reducing mobility (because selling a house and buying another is generally more costly than moving between rented houses), thus lowering long-run economic growth. Argument still rages over this theory though.

What I think has been left out of the discussion so far (apologies if I've missed it from anyone else) is that countries with higher rates of home ownership also seem to have done worse out of the 'great recession' of the last few years. The chart below shows home ownership rates in Europe in 2009 (from Eurostat) against the change in per capita GDP between 2006 and 2011, adjusted for inflation (from the IMF). The size of the bubbles represents current GDP, also from the IMF.

The two countries on the left with lowest rates of home ownership are Switzerland and Germany, and both of them have actually seen positive per capita GDP growth in the last five years. On the far right you've got two very small countries with very high home ownership rates and very differing fortunes of late, Slovakia having posted pretty strong economic growth of 8% over the period and Estonia having lost about 9% of GDP. Of the bigger countries with home ownership rates over 70% only Norway and Belgium have grown over the period, while Italy, Spain, Portugal, Finland and the UK have all seen economic contractions. And then there's Greece down there at the bottom. Obviously this leaves out anything that has happened in 2012 so far or is about to happen, and it certainly looks at the moment as though the likes of Spain, Italy and Portugal are looking at more recession to come - possibly very deep and long ones if things go really awry.

So what should we make of this pattern? Is it just coincidence, or just the result of some other factor? It could, for example, just be that poorer countries have more home ownership (as above) and poorer countries did worse in the recession for some other reason. We would need some careful analysis to identify the real causal paths, but as far as I can see there has been zero academic work done on this so far. That's surprising, but it does at least leave a nice big gap for speculation to fill!

The key features of the great recession in most countries were/are bursting property bubbles and credit crunches. What a high rate of home ownership does is expose more households to asset price increases in the bubble phase (possibly increasing the risk of 'irrational exuberance') AND to big drops in wealth from falling house prices in the bust phase, which then lowers household spending as they try to restore their balance sheets. Meanwhile, the drop in bank lending freezes the owner occupied housing market, making it harder to move house unless the rental market can quickly expand. So you've got a combination of job losses (from the wider recession), lower consumer spending even where people haven't lost jobs, and barriers to mobility making it harder for markets to adjust.

Another way of putting it is that high rates of owner occupation make the wider economy vulnerable to falls in housing demand, because falling house prices make owners want to spend less. But in a country where most people rent, lower housing demand (e.g. through job losses) result in falling rents, which frees up money for higher spending in other areas, helping to stabilise the economy.

There may well be benefits to home ownership (e.g. owner occupiers may take better care of their homes and it may provide a more stable environment for children), and politicians tend to like it, but I think the experience of the last few years suggests there are potentially quite large downsides too.

Saturday 16 June 2012

Despite what I said before, maybe cycling casualty rates aren't strictly comparable between Britain and the Netherlands. How about fatality rates then?

Back in April I posted an analysis of fatal and serious casualty rates for cyclists in Britain and the Netherlands, which reached the eye-catching conclusion that "just over 500 British cyclists are killed or seriously injured in collisions with motor vehicles for every billion km cycled, over eight times the rate in the Netherlands". I used data from the British Department for Transport and the Dutch road safety institute SWOV, but as a couple of commenters pointed out these do not in fact seem to use completely consistent definitions of what constitutes a 'serious' injury, so the comparison might be misleading. For example, snigbo said,
On comparing serious injuries: as discussed in DfT rrcgb2010-6.pdf, GB "serious" includes all admissions to hospitals, many of whom will have a MAIS score of 1. Table 11 suggests that 28% of hospital-admitted cyclists were MAIS 1, so reducing the GB number by that amount would be appropriate.
There is also the problem that for both countries the casualty figures are based on what is reported to police, and there may be differential rates of under-reporting, particularly for incidents not involving motor vehicles.

These are valid concerns, so I've updated that post with a health warning over the data. I'm grateful to the commenters for pointing these issues out, and I apologise if anyone was misled.

Can we then make any useful comparisons between the two countries? Well, it may be tempting fate to go back to the same data sources, but as was also pointed out the data on fatality rates should in principle be more comparable. After all, a fatality is a fatality wherever you are, and you would also expect minimal problems of under-reporting.

The problem here is that the SWOV data on contributory factors in cycling fatalities includes a large number (a majority, in fact) of cases described as 'Not matched', i.e. they don't say whether a motor vehicle was involved or not [Update: Note, this doesn't affect the total fatality rate, which is known - it's just that not every case is allocated to a particular type of incident]. You can just exclude all these unmatched cases and look only at the breakdown of the remainder, which is what I have done in the chart below. Having been burned before I would be cautious about putting too much weight on the results, mainly because of the large number of 'not matched' cases in the Netherlands data, but they do at least seem to be telling a similar story to the previous data, i.e. that the relative risk posed by motor vehicles to cyclists is higher in Britain than in the Netherlands.