Archive for INED

capture-recapture homeless deaths

Posted in Statistics, Travel, University life with tags , , , , , , , on August 28, 2014 by xi'an

Paris and la Seine, from Pont du Garigliano, Oct. 20, 2011In the newspaper I grabbed in the corridor to my plane today (flying to Bristol to attend the SuSTaIn image processing workshop on “High-dimensional Stochastic Simulation and Optimisation in Image Processing” where I was kindly invited and most readily accepted the invitation), I found a two-page entry on estimating the number of homeless deaths using capture-recapture. Besides the sheer concern about the very high mortality rate among homeless persons (expected lifetime, 48 years; around 7000 deaths in France between 2008 and 2010) and the dreadful realisation that there are an increasing number of kids dying in the streets, I was obviously interested in this use of capture-recapture methods as I had briefly interacted with researchers from INED working on estimating the number of (living) homeless persons about 15 years ago. Glancing at the original paper once I had landed, there was alas no methodological innovation in the approach, which was based on the simplest maximum likelihood estimate. I wonder whether or not more advanced models and [Bayesian] methods of inference could [or should] be used on such data. Like introducing covariates in the process. For instance, when conditioning the probability of (cross-)detection on the cause of death.

Albert Jacquard (1925-2013)

Posted in Books, Statistics with tags , , , , , , on September 21, 2013 by xi'an

Albert Jacquard passed away last week. He was a humanist, engaged in the defence of outcasts (laissés pour compte) like homeless and illegal immigrants. He had a regular chronicle of two minutes on France Culture that I used to listen to (when driving at that time of the day). In the obituaries published in the recent days, this side of the character was put forward, while very little was said about his scientific legacy. He was a statistician, first at INSEE, then at INED. After getting a PhD in genetics from Stanford in 1968, he got back to INED as a population geneticist, writing in 1978 his most famous book, Éloge de la Différence, against racial theories, which is the first in a long series of vulgarisation and philosophical books. Among his scientific books, he wrote the entry on Probabilités in the popular vulgarisation series “Que Sais-Je?”, with more than 40,000 copies sold and used by generations of students. (Among its 125 pages, the imposed length for a  “Que Sais-Je?”, the book includes Bayes theorem and, more importantly, the Bayesian approach to estimating unknown probabilities!)