This essay sketches technical and non-technical issues around persistent identifiers (henceforth PIs) in a manner which makes no attempt to be complete. Our goal is to rescue the core notions from the obscurity which detail and completeness burdens them with. A reader willing to entertain the...

In a bold and risky political move the Greek prime minister Alexis Tsipras called for a referendum on June 27 2015 quitting ongoing negotiations with Greece's creditors in Brussels. The referendum framed as a yes or no question asked the Greek voters to decide whether or not they approve or...

I create a time series of weekly ratios of Google searches, in the US, on buying and selling in the Real Estate Category of Google Trends. I call this ratio the Google US Housing Market BUSE Index or simply the BUSE index. It expresses the number of "buy"-searches for each "sell"-search which,...

There is continuing debate about what explains cooperation and self-sacrifice in nature and in particular in humans. This paper suggests a new way to think about this famous problem. I argue that, for an evolutionary biologist as well as a quantitative social scientist, the triangle of two...

In a bold and risky political move the Greek prime minister Alexis Tsipras called for a referendum on June 27 2015 quitting ongoing negotiations with Greece's creditors in Brussels. The referendum framed as a yes or no question asked the Greek voters to decide whether or not they approve or...

On February 20 2015 Irish Premier Enda Kenny confirmed that a "yes-no" referendum on same sex marriage would be held on May 22 of the same year. A yes vote would legalise same sex marriage in Ireland. As the Irish premier put it, the vote was about "tolerance, respect and sensitivity". The...

Traffic jams are an important problem both on an individual and on a societal level and much research has been done on trying to explain their emergence. The mainstream approach to road traffic monitoring is based on crowdsourcing roaming GPS devices such as cars or cell phones. These systems...

Traffic jams are an important problem both on an individual and on a societal level and much research has been done on trying to explain their emergence. The mainstream approach to road traffic monitoring is based on crowdsourcing roaming GPS devices such as cars or cell phones. These systems...

An empirically founded and widely established driving force in opinion dynamics is homophily i.e. the tendency of "birds of a feather" to "flock together". The closer our opinions are the more likely it is that we will interact and converge. Models using these assumptions are called bounded...

This paper addresses the steep learning curve in Machine Learning faced by noncomputer scientists, particularly social scientists, stemming from the absence of a primer on its fundamental principles. I adopt a pedagogical strategy inspired by the adage "once you understand OLS, you can work your...