## Χ on stage

Posted in Kids, pictures, Travel, University life with tags , , , , , , , on September 11, 2013 by xi'an

A screen-shot of the video taken during my talk in Hong Kong (restricted to 2013 WSC attendants, I am afraid. Or not.), where I happened to be wearing my favourite (and only) Scotland rugby shirt with prominent  Χ labels…

## waterline (book review)

Posted in Books with tags , , , , , , , on September 1, 2013 by xi'an

Another book I received as a bedside gift at The Hospital, this one a gift from Magali. Waterline by Ross Raisin is the story of a Glaswegian former shipyard worker falling into a mental abyss of denial and grief after her wife died. She died from asbestos-related cancer, whose fibres were brought from the shipyard in Mick’s clothes. Mick seeks solitude and shuns contact with former colleagues and friends, seeing their return to a normal life as an aggression against his wife’s memory. When Mick cannot stay longer in his rented council  house in Glasgow, fearing eviction and with no money left, he moves to London where he first finds a job as a dishwasher that alienates him even further into a bubble where he can cut others out. He is fired after a while for taking a very passive part in a local union and within a few weeks he spirals down into homelessness. The second part of the book sees him getting out very slowly and very reluctantly out of this state, with no clear sign of any return to (whatever we could call) normality…

This is a far from perfect book and the second part feels contrived, with a sort of “happy ending” out of the bottom end of Mick’s life. Still, Waterline is a strong book that marked me because it left me with a strong impression that the same fall could happen to any of us, under the right (or rather wrong) … Raisin has a highly convincing way of describing the inner mental paths taken by Mick to stop seeing others, including his children, for not returning to his uncertain cab driver job, and for giving up too readily looking for jobs, shelters, or help. The homeless-ness pages are terrifying in their somehow warped version of normality, when the “lives” of Mick and of his (leading) companion of misfortune Brian follow some kind of predestined pattern, from avoiding security guards by moving around to finding accessible toilets, to stealing food from  delivery trucks, to tracking protected places to sleep away from the rough weather. At times, this feels like too much and too long, but I would support the idea that this is “exactly” (given my total lack of expertise in the matter…) reflecting the experience of those homeless men, with no future further than the next night or the next meal. The second part of the book also shows how hard it is to reconcile with a “normal” life, incl. a poignant chapter on Mike reuniting with his son uncomprehending why his father had not called for help.  A highly recommended read, if not exactly on the brightest side of life…

## the wasp factory (book review)

Posted in Books, Kids with tags , , , , on August 25, 2013 by xi'an

Following Ian Banks’ death two months ago, I decided to buy his first published novel, The Wasp Factory. After reading it, I feel sorry for not having read this book earlier, like when it appeared in 1984!, as I definitely consider The Wasp Factory a masterpiece, a standalone novel that establishes Ian Banks’s stand as a great writer (and which understandably launched Banks’ carrier).

“I killed little Esmerelda because I felt I owed it to myself and to the world in general. I had, after all, accounted for two male children and thus done womankind something of a statistical favour.”

The book tells a story that stands at the boundary of the fantastic, centred on Frank, a character that lives in a boy’s dream of weapons and secret ceremonies and auguries, alone with his dysfunctional father. It is actually never clear how much of the story is imaginary (imagined by Frank) and how much is real, from the murders of three siblings (!) to the attack of the giant rabbit to the role of the father. While Frank is apparently in his late teens, going to the pub and getting drunk, his mind seems stuck at a pre-teen stage as he worries about his catapult and carries around a bag of (animal) skulls for holding rituals and ceremonies. In many respects, The Wasp Factory reminded me of Lord of the Flies, with the same streaks of amoral cruelty and the opening on how children’s minds (could) operate when left to their own device (which is the case in the novel). Not only wasps evoke flies (!), but flies also play a major role in the novel (no more spoiler!). Verging on the Gothic, The Wasp Factory has however an additional humorous touch, from the many devices imagined by Banks to kill characters and animals to the absurd phone conversations with the equally mad brother Eric (who earlier set to burn local dogs…). Given the completely unexpected ending of the book, The Wasp Factory certainly requires a second reading to uncover all the clues that should (could?) have warned me about the conclusion. Brilliant!

## standing in another man’s grave

Posted in Books, Mountains, Travel with tags , , , , , , on July 13, 2013 by xi'an

“Just another night when he would not quite make it as far as the bedroom.” Standing in another man’s grave

Rebus is back indeed! When my friend Arnaud told me there was a new Rebus, I could not believe it: I thought Rankin had stopped the series with Rebus’ retirement, and one of the best possible endings (Rebus resuscitating his nemesis, Cafferty, and the superb title of Exit Music) to the series. Now, a new novel has appeared, Standing in another man’s grave, signifying Rebus return on the literary scene (and on the Scottish sleuthing scene as well).

“It’s an odd little country, this, isn’t it? I just mean it’s hard to fathom sometimes. I’ve lived here most of my life and I still don’t understand the place.” Standing in another man’s grave

So, a few years after his retirement (and a few years after the ‘last’ novel), Rebus reappears, as a civil assistant to a jeopardised cold case unit in Edinburgh. Unsurprisingly, Rebus cannot stay put and starts participating in a police investigation about the current disappearance of a young girl. With a possible link with earlier disappearances along the A9 road from Perth to Inverness… (A road with a surprising number of Scotch distilleries along the way, but this is a false trail!)

“A nation of 5 million huddled together as if cowed by the elements and the immensity of the landscape surrounding them, clinging to notions of community and shared history.” Standing in another man’s grave

Pretty soon, Rebus takes over the enquiry and without much backup (except from his former colleague Siobhan) figures out most of the clues leading to the thread common to those young girl disappearances. Pushing towards the resolution with means as grey and borderline as usual. Since part of the book is about Rebus trying to reapply for police work thanks to a new law and the Complaints inspector Malcom Fox is trying to prevent this, the next book (as there will be a next book!) may see Rebus in more trouble.

“Rebus began to wonder if he’d ever been further from a pub in his life.” Standing in another man’s grave

This is Rebus’ Rankin back to life and still… I had the definitive impression that Rebus had gotten much older than the few years since his “retirement”. The story starts as if he had lost all contact with former colleagues and only kept in touch with retirees and dead policemen… Even the early dialogues with Siobhan sound contrived. This may actually be intentional. The story itself has nice sides (like the use of Twitter and Facebook by young officers or the elimination of the catalyst case that started the whole story), but the resolution requires too much of a suspension of disbelief. Too many drinks. Too much driving (even though all those names of towns reminded me of places I visited or wanted to visit in Scotland). Nonetheless enjoyable and a page-turner and paving the way to The Saints of the Shadow Bible… With Scottish independence looming in the back!

## thesis in Marseille

Posted in Books, Statistics, Travel, University life with tags , , , , , on July 4, 2013 by xi'an

Today, I went to Marseille for a PhD thesis defence: I biked to the RER train station (yay!) and the early (7am) flight was smooth, with clear views of nuclear plants along the way… I had previously and critically refereed the thesis, called “Essays on on the econometrics of inequality and poverty measurements” ; despite its strongly applied economics title it indeed was primarily an econometric work about mixtures and quantile regression. The thesis author and PhD incumbent Abdoul Aziz Ndoye being from Senegal, he had prepared a buffet after the defence with Senegalese (yummy) delicacies that I definitely enjoyed after such an early (Oat Squares, thanks to A&C.!) breakfast. (Actually, Aziz had presented a poster in Kyoto so some of you may have met him already!) The afternoon train ride to Montpelier was smooth as well, with nice views of Provençal villages along the way. (Too bad the train line does not stick more to the coastline, though.)

While the part on mixtures was rather traditional (still using Chib’s approach to evaluate marginal likelihoods and decide about the number of components in the mixture, while “resolving” the label switching problem by using assymmetric priors based on the sample quantiles [ok, "priors"!]), I got more interested in the quantile regression part. Maybe because quantile regression is mostly new to me, I have some difficulties in getting the motivation for (regular) quantile regression: I would see an estimation of the whole conditional cdf as linear in the regressor as a more natural goal than picking one or several probability levels to estimate the corresponding quantile. Also, the thesis follows an alternative approach called RIF where the density of the observables y is first estimated by a mixture of (log-)normals and then a quantile regression is operated on

$q_\tau+\mathbb{I}_{y>q_\tau}/f_Y(q_\tau),$

reintroducing the explanatory variables after estimating a joint density on the y’s, which puzzles me as well. (Note that this part of the thesis, written jointly with Michel Lubrano, got a Best Presentation Prize at the Scottish Economics meeting in 2012 and got published in the associated journal.) Overall, this is an innovative and interesting piece of work, even though it cannot be completely envisionned as a Bayesian resolution.