A simple model of process innovation is proposed, where firms learn about their ideal production process by making prototypes. We build around this a dynamic general equilibrium model, and derive conditions under which diversified and specialised cities coexist. New products are developed in...

This paper revisits a classical inquiry by addressing the question of localization and urbanization economies. We propose that specialization and diversity may offer externalities operating at different spatial scales. Using high-resolution geo-coded plant-level panel data for Swedish cities...

This paper introduces a model where new products are introduced by entrepreneurs or innovating firms in a quasi-temporal setting. Market conditions are characterized by monopolistic competition between varieties belonging to the same product group, where varieties can become obsolete over time...

This paper revisits a classical inquiry by addressing the question of localization and urbanization economies. We propose that specialization and diversity may offer externalities operating at different spatial scales. Using high-resolution geo-coded plant-level panel data for Swedish cities...