Which signals are important in gaining attention in science? For a group of 1,371 scientific articles published in 17 demography journals in the years 1990-1992 we track their influence and discern which signals are important in receiving citations. Three types of signals are examined: the...

We study a two-stage R&D project with an abandonment option. Two types of uncertainty influence the decision to start R&D. Demand uncertainty is modelled as a lottery between a proportional increase and decrease in demand. Technical uncertainty is modelled as a lottery between a decrease and...

We address the notion of dynamic, endogenous diversity and its role in theories of investment and technological innovation. We develop a formal model of an innovation arising from the combination of two existing modules with the objective to optimize the net benefits of diversity. The model...

The concentration of people with diverse socio-cultural backgrounds in particular geographic areas may boost the creation of new ideas, knowledge spillovers, entrepreneurship, and economic growth. In this paper we measure the impact of the size, skills, and diversity of immigration on the...

Portuguese strategic choices regarding innovation and R&D policy have, over the past two decades, produced various positive achievements, in which the regions of Lisbon and Algarve have taken the lead, and are the only ones in the country to converge towards the European average growth rate....

This paper examines how a radical technological innovation affects alliance formation of firms and subsequent network structures. We use longitudinal data of interfirm R&D collaborations in the biopharmaceutical industry in which a new technological regime is established. Our findings suggest...

We demonstrate the possibility of shake-out of firms and emergence of inter-firm heterogeneity along the (socially optimal) dynamic equilibrium path of a competitive industry with free entry and exit, even when there is no uncertainty and all firms are ex ante identical with perfect foresight....

The importance of knowledge spillovers for achieving innovation and economic growth is widely recognized. It is not straightforward which type of spillovers is most effective: intra-sectoral spillovers or inter-sectoral spillovers. We investigate this controversy using a model of regional...

We analyze the impact of obsolescence of economic inventions by incorporating maintenance costs in the endogenous growth model of expanding product varieties. This contrasts with the existing literature, which ignores maintenance costs and uses the model of quality improvements to describe...

Innovation and technological change are central to the quest for regional development. In the globally-connected knowledge-driven economy, the relevance of agglomeration forces that rely on proximity continues to increase, paradoxically despite declining real costs of information, communication...