National Bank of Poland leads on helping Ukraine’s currency

Ukrainian refugees see their currency hardly convertible at fair rates or even accepted. The lack of liquidity will also hit Ukraine’s government urgent expenses (medical supplies or weapons). The National Bank of Poland (NBP) offered a comprehensive financial package to address these problems. Firstly, it enabled the refugees to exchange the currency at a nearly …

Evidence-based quick wins in reducing oil demand

Following the Russia invasion on Ukraine an oil supply shock is expected and what is worse there may be no supply increase from OPEC+ . A way out is to cut the demand as advised by IEA. The proposed steps are quick-wins: easy to implement and reverse while having measurable and significant impact. The overall …

Quantitative overview of Nord Stream 2 issues

The briefing document of the European Parliament offers a quantitative and comprehensive view on the issues with Nord Stream 2. This excellent figure alone explains a lot: It may be interesting to realise that the points this document makes are underrepresented in popular press such as BBC. These concerns are discussed in measurable terms: The …

Iron logic defeats strawman

The straw man rhetorical technique is widely used: from scientific reviews (academia), through job interviews (industry) to the political discourse (international relations). The idea is simple: you distort arguments or opposing views to easier refute them. Not only is this trick popular, but proven successful statistically. The best weapon against it is logically strict reasoning. …

Can Russia defend its economy from sanctions?

While western leaders are proud of imposing largest sanctions ever, it seems that Russia can withstand the crisis longer than some expect. The following two points, underrepresented in popular media, support this claim: Historical AnalogyRussia’s went through 2014 financial crisis, where the currency significantly lost its value (from mid 30-s to around 80 for one …

Banks in Austria block financial help amid war on Ukraine

Amid the Russia’s invasion, some banks blocks money transfers to Ukraine. This effectively undermines the help efforts of both the international community and the expats. Here comes the wall of shame: a picture is worth thousand words: Poland does the right thing: polish banks offered free transfers to Ukraine.

Demystifying TestDom

Recruiters nowadays use online timed tests when screening developers. I recently looked at Python & Algorithms Hard questions at TestDome. While the timing and hints seem to push towards implementing tricks from scratch, for the quality in long term it is better to structure the problem and use established solutions (divide & conquer). The battery …

On Subgaussian Concentration of Missing Mass

The problem of missing mass goes back to the cryptographic work of Good and Turing during WWII, but has been also studied in the context of linguistic, ecology, and by probability theoreticians. The missing mass is defined as the weight of elements not observed in a sample, due to pure chance: Such an event and …

Approximating Tails of Beta Distribution

Beta distribution is ubiquitous in statistics, but particularly popular in real-world modeling. The beta-binomial model is perhaps the most known example, given the recent interest in Bayesian inference. But it was in use nearly 50 years ago, for example in toxicology. Unfortunately, computing probabilities from the density depends on intractable incomplete beta integrals. This creates …