This paper discusses a model of vertical and horizontal product differentiation within the Dixit-Stiglitz framework of monopolistic competition. Firms compete not only in prices and horizontal attributes of their products, but also in the quality that can be controlled by R&D activities. Based...

Agro-biodiversity can provide natural insurance to risk averse farmers. We employ a conceptual ecological-economic model to analyze the choice of agrobiodiversity by risk averse farmers who have access to financial insurance. We study the implications for individually and socially optimal...

Agro-biodiversity can provide natural insurance to risk-averse farmers by reducing the variance of crop yield, and to society at large by reducing the uncertainty in the provision of public-good ecosystem services such as e.g. CO2 storage. We analyze the choice of agro-biodiversity by...

Strong sustainability, according to the common definition, requires that different natural and economic capital stocks have to be maintained as physical quantities separately. Yet, in a world of uncertainty this cannot be guaranteed. To therefore define strong sustainability under uncertainty in...

This paper discusses a model of the New Economic Geography, in which the seminal core-periphery model of Krugman (1991) is extended by endogenous research activities. Beyond the common anonymous consideration of R&D expenditures within fixed costs, this model introduces vertical product...

A labor matching model with nominal rigidities can match short-run movements in labor's share with some success. However, it cannot explain much of the behavior of employment, vacancies, and job flows in postwar US data without resorting to additional shocks beyond monetary policy and...

The consequences of cylical contingencies in unemployment insurance systems are considered in a search-matching model allowing for shifts between "good" and "bad" states of nature. An argument for state contingencies is that insurance arguments are stronger and incentive effects weaker in bad...

When taken to examine disinflation monetary policies, the current workhorse DSGE model of business cycle fluctuations successfully accounts for the main stylized facts in terms of recessionary effects and sacrifice ratio. We complement the transitional analysis of the short-run costs with a...

We analyze determinacy and stability under learning (E-stability) of rational expectations equilibria in the Blanchard and Galí (2006, 2008) New-Keynesian model of inflation and unemployment, where labor market frictions due to costs of hiring workers play an important role. We derive results...