In this work we present a number of urn models in which, contrary to standard Polya urns, the number of competing alternatives is not given from the outset but may increase with the arrival of innovations. We begin by describing a variant of Polya urns, first introduced by Fred Hoppe, in which...

This article presents a model of sequential decisions about investments in environmentally dirty and clean technologies, which extends the path-dependence framework of Arthur (1989). This allows us to evaluate if and how an economy locked into a dirty technology can be unlocked and move towards...

We propose a behavioural model of technological change with evolutionary switching between boundedly rational costly innovators and free imitators, and study the endogenous interplay of innovation decisions, market price dynamics and technological progress. Innovation and imitation are strategic...

We consider firms' choices between a clean technology that benefits, and a dirty technology that harms, the environment. Green firms are more suited to the clean, and brown firms are more suited to the dirty technology. We use a model derived from complexity theory that takes account of true...

This article presents a model of sequential decisions about investments in environmentally dirty and clean technologies, which extends the path-dependence framework of Arthur (1989). This allows us to evaluate if and how an economy locked into a dirty technology can be unlocked and move towards...

In this work we present a number of urn models in which, contrary to standard Polya urns, the number of competing alternatives is not given from the outset but may increase with the arrival of innovations. We begin by describing a variant of Polya urns, first introduced by Fred Hoppe, in which...