Category Archives: Academic

Monty Hall Problem


Glenelg, Scotland

The Monty Hall problem usually features goats, not sheep.  But the grazing herd above does not mind.  I recently introduced the Monty Hall problem to someone who, like most people newly exposed to the problem, expressed dismay at the solution.  Today, someone posted the problem on 3 Quarks Daily (one of my favorite blogs).  So, it’s only natural that I should re-post here.  The problem demonstrates the inability of most people to grasp the nature of probability.  Even mathematicians have struggled to comprehend the problem.  Still, the solution is not in doubt.

From the Roof, San Fran.

From the Roof, San Fran.

If I didn’t know better, I’d say Gary Gutting was reading my blog: Professor Gutting discusses the exact problem I described in a recent blog – the proliferation of scientific studies in the media – and the fact that these studies are misrepresented.  Gutting’s suggestion for a coding system is well received.  As he points out, there are different types of studies – ones that suggest a correlation, and those that establish a causal link.  In many cases, the media fails to distinguish between the two.


Krugman’s take on the R&R debacle:

From Tetris to coffee stains, an interesting article on the fascinating topic of universality:

Here’s an article from the Chronicle on the problems facing the fashionable theories of today’s physics.  Again, refer to Peter Woit for a full treatment of symmetry and string theory.

Getting Granular…

espresso, Union Square, San Francisco

espresso, Union Square, San Francisco

Oh boy.  In the last post, I discussed the importance of replicating research as a mechanism in the scientific process.  Replication is especially important when the original research informs policy decisions and influences political actors.  Well, it looks like a seminal paper (RandR) in economics by Reinhard-Rogoff (followed by their book (“This Time is Different: Eight Centuries of Financial Folly“) contains some outcome-changing errors.

You might be thinking…well, so what?  Some nerdy economics paper turns out to be off the mark.  Well…the problem here is – when it comes to debating economic policies for countries (think U.S. and E.U.) –  the paper in question is the most influential in the aftermath of the global economic crisis.  Since publication, it has been cited about 450 times in related work.  (see here for a fuller explanation of the issues with the R&R work).  The three main issues that distorted R&R’s results were: selective exclusions, unconventional weighting, and a coding error.  The coding error is really quite unbelievable.  Basically, it’s a spreadsheet error.  Therefore, the key research that provided the basis for global moves toward austerity turns out to be partly based on someone messing up in Excel.

What’s interesting is how theories in social sciences go from paper to book to influencing policy with very little attempt  to replicate the original results.  Obviously, not the first time this has happened.  Still, scholars need to wake up and smell the coffee.