Empirical evidence shows that research is being carried out more in cooperation or in collaboration with others, and the networks described by these collaborative research activities are becoming more and more complex. This phenomenon brings about new strands of research questions and opens up a...

The spatial agglomeration of economic activities play a crucial role on productivity but the composition of such an agglomeration is what really matters. There exists an ongoing debate between the predominance of the effects of agglomeration from specialization and diversity. This paper aims to...