Posts Tagged ‘risk’

The best interview question I’ve ever been asked

In 2005 I was interviewing for a job as Risk Manager with Genworth Financial. I was working a gig up in Armonk, NY so I hopped a car to the GNW office and met with Mark Griffin, at that point the Chief Risk Office (CRO) for GNW. After some small talk, Mark asked me the [...]

Third, and Hopefully Final, Post on Correlated Random Normal Generation (Cholesky Edition)

When I did a brief post three days ago I had no plans on writing two more posts on correlated random number generation. But I’ve gotten a couple of emails, a few comments, and some Twitter feedback. In response to my first post, Gappy, calls me out and says, “the way mensches do multivariate (log)normal [...]

Even Simpler Multivariate Correlated Simulations

So after yesterday’s post on Simple Simulation using Copulas I got a very nice email that basically begged the question, “Dude, why are you making this so hard?” The author pointed out that if what I really want is a Gaussian correlation structure for Gaussian distributions then I could simply use the mvrnorm() function from [...]

Stochastic Simulation With Copulas in R

A friend of mine gave me a call last week and was wondering if I had a little R code that could illustrate how to do a Cholesky decomposition. He ultimately wanted to build a Monte Carlo model with correlated variables. I pointed him to a number of packages that do Cholesky decomp but then [...]

I don’t even know how wrong I am!

I’ve been a long time reader of the blog “Messy Matters” (which invokes terrible images now that I am potty training a toddler). The authors, Sharad Goel and Daniel Reeves are academics who work in the Microeconomics and Social Systems (get it, MESS?!?) lab funded by Yahoo!. (What does Strunk and [...]

Poultry House Risk

There’s an interesting article in the WSJ this week about poultry farmers who grow for Pilgrim’s Pride (PPC). PPC is in bankruptcy and have canceled grower contracts with 400+ poultry growers. In poultry farming the farmers own the chicken houses and provide the labor but the poultry company (Pilgrim’s Pride, Tyson, Perdue, etc) own the [...]

Mandelbrot and Taleb on PBS

Let me start by saying that I like Nassim Nicholas Taleb and BenoĆ®t Mandelbrot quite a lot. I don’t agree with them all the time, but that is generally true of people I like. I recall reading Mandelbrot’s book The Misbehavior of Markets: A Fractal View of Financial Turbulence some years ago and being struck [...]