This paper summarizes some of the most influential economic concepts developed by Gottfried Haberler, a leading economic theorist of the 20th century. The importance of his theories for modern economic thought cannot be overestimated. His ideas on price indices, applied opportunity costs for...

he sociological literature on social networks emphasizes by and large positive network effects. Negative effects of such networks are discussed rather rarely. This paper tackles negative effects by applying economic theory, particularly neoclassical theory, new institutional theory and the...

This paper focuses on transaction tasks as seen on the micro level. We suggest how transaction tasks can be measured by the official statistics. The article complements a previous one by Chobanov, Egbert and Gyuredjeklieva (2006) published in this journal and discusses the weaknesses of existing...