risk

The basics of Value at Risk and Expected Shortfall

October 23, 2012 | Pat

Value at Risk and Expected Shortfall are common risk measures.  Here is a quick explanation. Ingredients The first two ingredients are each a number: The time horizon — how many days do we look ahead? The probability level — how far in the tail are we looking? Ingredient number 3 is a prediction ... [Read more...]

Reshaping the IT world

February 16, 2012 | Markus Gesmann

During my university time I worked on the IT help desk for a while. One day I received a call from a professor, who said that his printer had stopped working. So I asked him, if there was a message on the display and if he could read it to ...
[Read more...]

Misleading Statistics: Too much risk without a financial adviser?

November 22, 2011 | BioStatMatt

This popular article references a report by financial consulting firms that makes a fairly convincing argument (even though they mostly neglect inferential statistics, and some parts of their argument are misleading, or otherwise not convincing) that 401(k) participants who accept "help" from financial experts take less risk and have better ... [Read more...]

Review of “Risk and Meaning” by Nicolas Bouleau

September 5, 2011 | Pat

The subtitle is: Adversaries in Art, Science and Philosophy. Executive Summary Genius or madness? I haven’t decided. Irreversibility of interpretation The book drives home that once we decide how something is we can’t go back to our state of innocence. Figures 1 through 3 exhibit this idea via a randomly ... [Read more...]

Factor models of variance in finance

March 7, 2011 | Pat

In “What the hell is a variance matrix?” I talked about the basics of variance matrices and highlighted challenges for estimating them in finance.  Here we look more deeply at the most popular estimation technique. Models for variance matrices The types of variance estimates that are used in finance can ...
[Read more...]

Normal market accidents

January 17, 2011 | Pat

We think of accidents as abnormal events, but there is “normal accident” theory.  We don’t think of accidents happening in markets, but they do.  That’s why it’s called a market crash. For normal accidents to come into play, two conditions need to hold: the system is complex ...
[Read more...]

Blog year 2010 in review

December 30, 2010 | Pat

The blog year started in August and consists of 30-something posts.  Here is a summary. Quant concepts backtesting: Backtesting — almost wordless cointegration: American TV does cointegration efficient frontier: Anomalies meet volatility implied alpha: Implied alpha — almost wordless portfolio theory: Ancient portfolio theory random walk: The tightrope of the random walk ...
[Read more...]

Tennis and risk management

December 16, 2010 | arthur charpentier

As mentioned already here, while we were going to Québec City for the workshop, we had interesting discussions in the car, and Maciej mentioned an article recently published in The Actuary, Hence, I wanted to discuss (extremely) rare event probabi...
[Read more...]

Some ideas on communicating risks to the general public

December 3, 2010 | dan

SOME EMPIRICAL BASES FOR CHOOSING CERTAIN RISK REPRESENTATIONS OVER OTHERS This week DSN posts some thoughts (largely inspired by the work of former colleagues Stephanie Kurzenhäuser, Ralph Hertwig, Ulrich Hoffrage, and Gerd Gigerenzer) about communicating risks to the general public, providing references and delicious downloads where possible. Representations to ... [Read more...]

Even Simpler Multivariate Correlated Simulations

August 31, 2010 | JD Long

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 ... [Read more...]

Stochastic Simulation With Copulas in R

August 30, 2010 | JD Long

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 ... [Read more...]

What the hell is a variance matrix?

August 25, 2010 | Pat

When I first came to finance, I kept hearing about “risk models”. I wondered, “What the hell is a risk model?” Of course, I didn’t say this out loud — that would have given the game away.  My wife has strict instructions that she is to be the only one ...
[Read more...]

Never miss an update!
Subscribe to R-bloggers to receive
e-mails with the latest R posts.
(You will not see this message again.)

Click here to close (This popup will not appear again)