I sportsed all over Prague

On Sunday the 3rd of May, 2015 (two weeks before I officially turn old), I finally achieved a life-long ambition of running a marathon. I ran in the Prague Marathon organised by RunCzech. My official race time was 4:08:02, but since it took me over five minutes to cross the start line, my actual time was 4:02:24.

My training was not particularly rigorous — the longest I had run beforehand was 27km (about 16.5 miles) — and I was really only aiming to finish, so to finish so close to four hours is incredibly gratifying. I spent the vast majority of the race ahead of the 4-hour pace setters, but hit my own version of the wall in the 38th kilometre. These two charts summarise my experience. The first chart lists my times for each kilometre, with the red line being the rate needed to achieve four hours (the peak in the 21st km is a pee break). The second gives my time relative to that 4-hour target (in seconds). At the 34km mark, I was 244 seconds (4 minutes, 4 seconds) ahead of the 4-hour pace, meaning that I lost roughly six and a half minutes in the last 8.2 km.


The biggest thing I learned from the experience is that there is no such thing as “the” wall — there are at least three walls!

The first wall is simple glycogen depletion, possibly combined with dehydration. I’m pretty sure this was not an issue for me, although I am starting to wonder (see below). I had stuffed my face with pasta (and protein) for days beforehand, I downed a Clif Bar immediately prior to the race and I was munching on a Clif Shot Blok every 5km. I was also drinking water regularly, to the point of needing to stop to pee at the half-way mark. Having said that, I now realise that I was only consuming about 20g of carbs per hour, which is considerably less than the commonly recommended 40-60g. I never experienced any of the usual glycogen depletion symptoms, like a brain fade, though. I always felt like I had energy.

The second wall is psychological. Since my longest ever run beforehand was only 27 km, I was acutely aware of the distance once I headed north of 25km and had to talk my way through it in the 28-30 km range. Certainly once I’d gotten to 32 km and was able to tell myself “10 km to go”, this issue seemed to pass completely.

The third wall, which I had not considered at all beforehand, was a dramatic emergence of muscle pain in my quads from about 35km onwards. At first, it just felt like muscle burn from doing hill sprints, but it got worse and just after the 37km mark it became so bad that I had to stop and walk. I tried stretching, but that somehow only made it worse, into a blinding pain that shut out almost all other sensory experience.

I walked and occasionally shuffle-jogged for the next 2km before the pain started to ease and I was able, with a grit-the-teeth-and-focus-like-a-goddamn-laser sort of effort, to keep myself jogging constantly for the final 3 km. Watching the 4-hour pace setters run past me while I was walking was not a pleasant experience.

It was not a pulled muscle (a muscle strain) — it was in both legs and it eased over the next couple of days as I recovered in ways that a strain would not. I also do not think it was glycogen depletion, as I (believe that I) remained lucid and had energy throughout. Instead, I think it was “dead quads”, of the sort described here and here. If I’m correct, then it amounted to insufficient training and, in particular, insufficient strength training. Weirdly enough, it also suggests that if I had stopped and stretched my hamstrings halfway through the event, it might not have been so bad.

You can see how poor my form was at the end here (notice how robotic the leg movements are, and how I’m just lifting my feet and then dropping them like bricks):

If that makes it seem like I’m disappointed, I promise that I’m not! It was an incredible experience that I enjoyed immensely and would encourage anybody to try. I’m already scoping out my second …

Digital currencies, including Bitcoin

Back in 2011, I wrote a post about Bitcoin.

In March 2013 I started employment at the Bank of England and this blog went into dormancy.

My view evolved somewhat since then. Interested readers might care to read two new articles in the Bank’s Quarterly Bulletin on digital currencies. I was a co-author on both of them.


That link also includes two videos (hosted on YouTube), one of which features my head talking awkwardly.

Now dormant

Since March 2013 I have been employed by the Bank of England and, as such, am unable to offer public comment on matters that might relate to the work of the Bank or politics in the UK.

I may, at some point, return to blogging here on matters outside the domain of my work; but for now, this blog will remain dormant.

The Tesla vs. John Broder (of the NY Times) fiasco

(Updated to include all of Broder’s published pieces on the matter)

After their 2011 cock-up with their Top Gear review, you might be forgiven for thinking that Tesla had learned a valuable lesson.  Nope.

Here (10 Feb 2013) is the review by John Broder of the NY Times, in which he roundly disparages the Tesla Model S.  Elon Musk — Chairman, Product Architect and CEO of Tesla — firmly disputed Broder’s account of what happened.

Here (12 Feb 2013) is Broder’s second piece on the matter, in which he defends the allegations he made in the review.

Here (13 Feb 2013) is Tesla’s public response, including detailed logs of what the car was actually doing.  On the face of it, this appears to completely vindicate Musk (not to mention raise questions about Broder’s approach to journalism).

Here (14 Feb 2013) is Broder’s third piece, with a point-by-point reply to Tesla’s blog entry.  Many, if not all, of his points sound reasonable.

At this point, the whole thing is a he-said-she-said debacle.

None of that matters, though.

Tesla screwed up here, and badly. Not technically (i.e. from an engineering perspective), but definitely on the marketing side.

It might be cynical, but looking into the past work of the dude assigned to evaluate your product is just basic PR management. What kind of marketing director doesn’t sit down and think about what prior biases any given reviewer might have? I suppose I can understand failing to think about it the first time, but twice is just plain stupid.

Especially because of the fiasco with Top Gear and Broder’s (apparently) demonstrated prior beliefs, but fundamentally just as a basic courtesy, why didn’t Tesla tell Broder and the NY Times up front that everything would be logged? Heck, why not ask (or even insist) beforehand that the log data be made publicly available alongside the article? Isn’t a near endless supply of data about the car a selling point?

Tesla is a near perfect example of the simple fact that good engineering and good design are not sufficient to produce a successful product.

Nobody approaches a new thing (product, topic, event, whatever) with a completely open mind. Everybody has pre-conceived notions that shape (i.e. bias) their experiences.  It’s called “being human.” Failure to recognise and work with that simple fact demonstrates an almost child-like naivety. Seriously, does everybody at Tesla think that Apple is successful only because of their design and engineering?

Tesla fans are going to feel smug over this whole affair.  Telsa itself is going to lose potential customers.


Hate too-big-to-fail banks? Then you should love CDOs …

A random thought, presented without much serious consideration behind it:

The more we do away with too-big-to-fail banks, the more we need CDOs and the like to provide risk and liquidity transformation.

Suppose we replace one giant, global bank with many hundreds of small banks. Each small bank will end up specialising in specific industries or geographic regions for reasons of localised economies of scale. There exists idiosyncratic risk — individual industries or geographic regions may boom or go belly up. A giant, global bank automatically diversifies away all that idiosyncratic risk and is left with only aggregate (i.e. common-to-all) risk. Individually and in the absence of CDOs and the like, idiosyncratic risk will kill off individual banks. With CDOs and their ilk, individual banks can share their idiosyncratic risk without having to merge into a single behemoth.

In the event of a true aggregate shock, the government will end up needing to bail out the financial industry no matter what the average bank size because of the too many to fail problem.

There are problems with allowing banks to become TBTF.  They end up being able to raise funding at a subsidised rate and their monopoly position allows them to charge borrowers higher rates, both contributing to rent extraction which is both economically inefficient (the financial industry will attract the best and the brightest out of proportion to the economic value they contribute) and fundamentally unfair. Worse, the situation creates incentives for them to take excessive risks in their lending, leading to a greater probability of an aggregate shock actually occurring.

But we are now trying to kill off TBTF in a world in which credit derivatives have either vanished altogether or are greatly impaired. On the one hand, that reduces aggregate risk because we take away the perverse incentives offered to TBTF banks, but on the other hand, it also reduces our ability to tolerate idiosyncratic risk because we take away the last remaining means of diversification.