We present conditions for the emergence of singularities in DGE models. We distinguish between slow-fast and impasse singularity types, review geometrical methods to deal with both types of singularity and apply them to DGE dynamics. We find that impasse singularities can generate new types of...

We develop a dynamic general equilibrium model of imperfect competition where a sunk cost of creating a new product regulates the type of entry that dominates in the economy: new products or more competition in existing industries. Considering the process of product innovation is irreversible,...

This paper surveys the link between imperfect competition and the effects of fiscal policy on output, employment and welfare. We examine static and dynamic models, with and without entry under a variety of assumptions using a common analytical framework. We find that in general there is a robust...

This paper surveys the link between imperfect competition and the effects of fiscal policy on output, employment and welfare. We examine static and dynamic models, with and without entry under a variety of assumptions using a common analytical framework. We find that in general there is a robust...

We develop a simple Ramsey model with numerous Cournotian industries where entry generates an endogenous markup. The model produces two different regimes: a monopoly and an oligopoly one. We provide a rigorous study of non-smooth dynamics and we also analyse the global dynamics of the model,...

We compute average mark-ups as a measure of market power throughout time and study their interaction with fiscal policy and macroeconomic variables in a VAR framework. From impulse-response functions the results, with annual data for a set of 14 OECD countries covering the period 1970-2007, show...

In this paper we develop a general model of an imperfectly competitive small open economy. There is a traded and non-traded sector, whose outputs are combined in order to produce a single final good that can be either consumed or invested. We make general assumptions about preferences and...

This paper analyses an open economy Ramsey model with an endogenous labour supply without capital. The technology defines an optimal firm size. Changes to the number of firms is subject to adjustment costs, so that the entry dynamics is determined endogenously. We find that there is a short run...

This paper explores an equilibrium model for industry entry dynamics and technological change. We focus on the share valuation of firms in the transition as technology changes, and whether or not share prices are always increasing when technology improves. We find that there can be a U-shaped...

In this paper, we see how much the average monthly frequency of price changes ties down the behavior of firms in steady-state in terms of the average length of price-spells across firms. We use the UK CPI data at the aggregate and sectoral level and find that the actual mean is about twice the...