In this paper we investigate the characteristics of the citation distributions of the 500 universities inthe 2013 edition of the CWTS Leiden Ranking. We use a WoS dataset consisting of 3.6 million articles published in 2003-2008 with a five-year citation window, and classified into 5,119...

The usual solution to the aggregation problem of heterogeneous fields in the all-sciences case relies onthe prior normalization of the raw citations received by any publication. In this paper, we propose analternative solution that does not require any prior field-normalization. The citation...

This paper studies the assignment of responsibility to the participants in the case of co-authored scientific publications. In the conceptual part, we establish that the key shortcoming of the full counting method is its incompatibility with the use of additively decomposable citation impact...

This paper analyzes a sample of economists from two sources: faculty members working in2007 in a selection of the 81 top Economics departments in the world, and Fellows of the Econometric Society active at that date but working elsewhere in other institutions. Productivity is measured in terms...

This paper exploits a unique 2003-2011 large dataset, indexed by Thomson & Reuters, consisting of 17.2 million disambiguated authors classified into 30 broad scientific fields, as well as the 48.2 million articles resulting from a multiplying strategy in which any article co-authored by two or...

This paper has two main aims: (i) to criticize the diagnosis about the research performance of the EU contained in the so-called “European Paradox”, according to which Europe plays a leading world role in terms of scientific excellence, but lacks the entrepreneurial capacity of the U.S. to...

Waltman & Van Eck, in press, contains a systematic large-scale empirical comparison of classification-system-based versus source normalization procedures. A source-normalization procedure SNCS performs better than a normalization procedure based on the system where publications are classified...

We study the problem of normalizing citation impact indicators for differences in citation practices across scientific fields. Normalization of citation impact indicators is usually done based on a field classification system. In practice, the Web of Science journal subject categories are often...

In this paper, we develop a new methodology for comparing normalization procedures based on different classification systems. Firstly, a pair of normalization procedures should be compared using their own classification systems for evaluation purposes. Secondly, when the two procedures are...

This paper studies the role of extremely highly cited articles in two instances: the measurement of citation inequality, and mean citation rates. Using a dataset, acquired from Thomson Scientific, consisting of 4.4 million articles published in 1998-2003 in 22 broad fields with a five-year...