We develop a simple model of the foreign exchange market in which agents optimize their portfolio and use different forecasting rules. They check the profitability of these rules ex post and select the more profitable one.This model produces two kinds of equilibria, a fundamental and a bubble...

In this paper we develop a model of the exchange rate. The existence of transactions costs introduces an important non-linearity. Agents have different beliefs about the future exchange rate. We show that this simple model creates great complexity in the market which is characterised by the fact...

We study the environmental and economic effects of public abatement in the presence of multiple stable steady-state ecological equilibria. Under shallow-lake dynamics (SLD), the isocline for the stock of pollution features two stable branches, a good and a bad one. Assuming that the ecology is...

Robust decision making implies welfare costs or robustness premia when the approximating model is the true data generating process. To examine the importance of these premia at the aggregate level we employ a simple two-sector dynamic general equilibrium model with human capital and introduce an...

We develop a two-sector, two-country model where trade is driven by technological differences. Each country is populated by large number of heterogeneous workers distinguished by their level of skills. Given that one country has a technological advantage in the skilled intensive good when we...

This paper sets up a general oligopolistic equilibrium model with unionized labor markets. By accounting for productivity differences, the model features profit and wage differentials across industries. We use this setting to study the impact of trade liberalization on employment, welfare, and...

We investigate externalities in higher education enrollment over the course of development in a two-sector model. Each sector works with only one type of labor, skilled or unskilled, and individuals are differentiated according to their cost of acquiring human capital. Both sectors exhibit...

This paper develops a two-sector R&D-based growth model with congestion effects from increasing urban population density. We show that endogenous technological progress causes structural change if there are positive productivity spillovers from the modern to the traditional sector and Engel's...