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...

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...

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...

We present the operationalized Toll Index, which is a new type of early indicator for the German business cycle. We present the basic idea and document the power of the indicator for the purpose of nowcasting. The data will be regularly available at the IDSC, the data bank center of IZA and will...