Lars P. Syll

Do complex numbers exist? (wonkish) .[embedded content]

Yours truly has invited five of his colleagues to share a Christmas lunch with him around the circular dinner table in his kitchen. Unfortunately, two of the colleagues are not on speaking terms with each other, so they cannot be seated together. In how many ways can we be seated around the table?

How to ensure that models serve society • Mind the assumptions — assess uncertainty and sensitivity. • Mind the hubris — complexity can be the enemy of relevance. • Mind the framing — match purpose and context. • Mind the consequences — quantification may backfire. • Mind the unknowns — acknowledge ignorance. Andrea Saltelli, John Kay, Deborah Mayo, Philip B. Stark, et al. Five principles I think modern times “the model is the message” economists...

.[embedded content]

Economics beyond Krugman, Mankiw, and Rodrik Economics students today are complaining more and more about the way economics is taught. The lack of fundamental diversity — not just path-dependent elaborations of the mainstream canon — and narrowing of the curriculum, dissatisfy econ students all over the world. The frustrating lack of real-world relevance has led many of them to demand the discipline to start developing a more open and pluralistic...

Gloria Thurn und Toxisch .[embedded content]

An easy one this week: Yours truly wants to distribute 30 one-dollar coins among his kids Linnea, David, and Tora. In how many ways can this be done if he wants all of them to get at least one coin? 

Mathematical modeling in economics If scientific progress in economics lies in our ability to tell ‘better and better stories’ one would, of course, expect economics journals to be filled with articles supporting the stories with empirical evidence confirming the predictions. However, the journals still show a striking and embarrassing paucity of empirical studies that (try to) substantiate these predictive claims. Equally amazing is how little one has...

Monte Carlo simulations — no substitute for thinking In some fields—physics, geophysics, climate science, sensitivity analysis, and uncertainty quantification in particular—there is a popular impression that probabilities can be estimated in a ‘neutral’ or ‘automatic’ way by doing Monte Carlo simulations: just let the computer reveal the distribution … Setting aside other issues in numerical modeling, Monte Carlo simulation is a way to substitute...

Selling deaf aids … .[embedded content]