TY - JOUR TI - Identifying geographic clusters: A network analytic approach N1 - Available online May 14, 2015 KW - Innovation clusters KW - Network analysis KW - Bio-pharmaceutical industry AV - public EP - 1762 ID - eprints2680 SP - 1749 UR - http://www.sciencedirect.com/science/article/pii/S004873331500013X SN - 0048-7333 VL - 44 PB - Elsevier Y1 - 2015/11// IS - 9 N2 - In recent years there has been a growing interest in the role of networks and clusters in the global economy. Despite being a popular research topic in economics, sociology and urban studies, geographical clustering of human activity has often been studied by means of predetermined geographical units, such as administrative divisions and metropolitan areas. This approach is intrinsically time invariant and it does not allow one to differentiate between different activities. Our goal in this paper is to present a new methodology for identifying clusters, that can be applied to different empirical settings. We use a graph approach based on k-shell decomposition to analyze world biomedical research clusters based on PubMed scientific publications. We identify research institutions and locate their activities in geographical clusters. Leading areas of scientific production and their top performing research institutions are consistently identified at different geographic scales. A1 - Catini, Roberto A1 - Karamshuk, Dmytro A1 - Penner, Orion A1 - Riccaboni, Massimo JF - Research Policy ER -