# Blog Archives

## Income distribution and Tour de France

July 21, 2014
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A few days ago, Jean-François Mignot published an interesting article entitled Tour de France 2014 : pourquoi le vainqueur gagne 100 fois plus que le 10e. In this article, we have the following graph, with the income of the cyclist, as a function of his final ranking (the data where downloaded from http://sportbuzzbusiness.fr/) > bike=read.csv( + "http://freakonometrics.free.fr/tourdefrance.csv", + sep=";",header=TRUE,dec=" ") >...

## Bayesian Wizardry for Muggles

July 11, 2014
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Monday, I will be giving the closing talk of the R in Insurance Conference, in London, on Bayesian Computations for Actuaries, as to be more specific, Getting into Bayesian Wizardry… (with the eyes of a muggle actuary). The animated version of the slides (since we will spend some time on MCMC algorithm, I thought that animated graphs could be...

## Statistics, and the Goldilocks Principle

June 26, 2014
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By the end of May, in Toronto, we had that great talk at the SSC by Jeff Rosenthal, on monte carlo techniques, and Jeff mention the name of “the Goldilocks principle” (it was in the contect of MCMC, and I did mention it in my talk in London on MCMC, when I discussed the value of the rejection rate...

## Conditional Distributions from some Elliptical Vectors

June 18, 2014
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$\boldsymbol{X}=(\boldsymbol{X}_1,\boldsymbol{X}_2)$

This winter, in my ACT8595 course, I asked my students (that was some homework) to prove that it was possible to derive the conditional distribution when we have a Student-t random vector (and to get the analytical expression of the later). But before, let us recall a standard result about the Gaussian vector. If  is a Gaussian random vector, i.e. then  has a...

## Tukey and Mosteller’s Bulging Rule (and Ladder of Powers)

June 16, 2014
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$Y_i=\beta_0+\beta_1 X_i+\varepsilon_i$

When discussing transformations in regression models, I usually briefly introduce the Box-Cox transform (see e.g. an old post on that topic) and I also mention local regressions and nonparametric estimators (see e.g. another post). But while I was working on my ACT6420 course (on predictive modeling, which is a VEE for the SOA), I read something about a “Ladder of...

## Box plot, Fisher’s style

June 4, 2014
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In a recent issue of Significance, I discovered an interesting – and amuzing – figure, about some box & beard plot, in Dr Fisher’s casebook: Beard the statistician in his den. In French, the box plot (introduced by John Tukey, not George Box, as discussed in a previous post) is popular under the name boîte à moustaches (box with a...

May 29, 2014
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This week, I discovered a picture on http://waitbutwhy.com/, which represent a (so-called) typical human life, in weeks, I found that interesting. But the first problem is that I don’t understand the limit, below: 90 years, that’s not the average life length. That’s not what you should expect to live when you get born. The second problem is that it cannot be...

## Allez les Bleus !

May 20, 2014
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In almost three weeks, the (FIFA) World Cup will start, in Brazil. I have to admit that I am not a big fan of soccer, so I will not talk to much about it. Actually, I wanted to talk about colors, and variations on some colors. For instance, there are a lot of blues. In order to visualize standard...

## Computational Actuarial Science

May 9, 2014
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After some delay, the book Computational Actuarial Science with R is now annonced for July 2014. I don’t know if we will be able to get copies for the R in Insurance conference, in London, but I guess everyone is working on it. And kindly, CRC sent me the following flyer, with some reduction code to save 20% (when ordering...

## There is no “Too Big” Data, is there?

April 23, 2014
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$Y_i\sim\mathcal{B}(p_i)$

A few years ago, a former classmate came back to me with a simple problem. He was working for some insurance company (and still is, don’t worry, chatting with me is not yet a reason for dismissal), and his problem was that their dataset was too large to run (standard) codes to get a regression, and some predictions. My...