Qualitätserwartungen und ethischer Anspruch bei der Lektüre von Blogs und von Tageszeitungen

Besides classical journalistic products, media users increasingly tend to read texts on the internet published by other users, as in weblogs. How do users navigate among these offers, how do they evaluate the quality, and which standards in terms of media ethics do they apply when reading weblogs compared to newspaper articles? Two empirical studies address these questions. In a survey, 702 internet users rated their theoretical expectations in terms of journalistic quality and compliance with ethical standards, comparing weblogs and daily newspapers. In a consecutive 2 × 2 experimental design, 120 participants read a journalistic text with varying source information (weblog/daily newspaper) and varying degree of adherence to ethical standards (ethically questionable/neutral). Participants then rated the quality of the text and its ethical standards. Results indicate that daily newspapers more than blogs are expected to deliver journalistic quality. But when read, texts are evaluated according to their content rather than their source. Ethically questionable texts in newspapers are disapproved as much as ethically questionable blog postings.     

The LeChatelier-Samuelson principle revisited

Within the context of a linear Leontief model, the LeChatelier-Samuelson principle examines the effects of an increase in some final demand on the output levels under the constraint that the production of certain goods is held at its original value. The principle states that the increase in any output is larger when fewer output levels are kept constant. The present paper discusses bounds for such incremental changes, second-order effects, the consequences on the markets for the products with restricted output levels, and generalizations of the original assumptions.I would like to thank two anonymous referees for their helpful comments.     

On invariant parametric covariance families

Summary In this note we characterize all linear transformations of random vectors which are invariant for a given parametric covariance family. Two one-dimensional covariance families are discussed in detail.     

The Impact of the 9/11 Events on the American and French Stock Markets

Markets reacted strongly to the World Trade Center attacks both in Europe and in the United States. The extent of this crisis was difficult to assess at the time, underlining the need for a specific tool to measure the magnitude of financial crises. A first measure was recently proposed and applied to the foreign exchange market by Zumbach et al. (2000a,b ). Their measure relies on an analogy with geophysics; the related index of market shocks (IMS) that we propose here is also the counterpart of the Richter scale used for earthquakes. We apply this measure on the French and the American stock markets to put large market events into perspective. The crisis triggered by the September attacks was actually the worst since 1987, and the ninth worst when compared to major historical ones.