This paper focuses on the possibility that financial markets require risk premia on holding sovereign debt of countries that appear vulnerable from a fiscal sustainability perspective. Both the level of debt as well as the rate of change of debt are assumed to impact on the risk premium. We analyze the impact of such an endogenous risk premium in a simple debt game between a monetary and a fiscal player, as introduced by [Tabellini (1986) Journal of Economic Dynamics and Control 10, 427–442]. The risk premium term adds a nonlinearity to the linear model in case risk premia are absent. We analyze outcomes in case of noncooperative open-loop Nash strategies and in case of cooperative strategies and consider the workings of the risk premium as a market-based disciplining device (in case of high debt) and adjustment rewarding device (in case of a declining debt trajectory).

The 1996 farm bill challenges agricultural producers to pursue conservation objectives while allowing flexibility and reducing subsidies. The nature of this challenge for semi-arid rainfed, wind-erosion-prone agriculture is explored via a behavioral model. Simulations of farm-firm decision making under scenarios in the southern Texas High Plains are evaluated. Results indicate that the removal of subsidies, while lowering farm incomes, does not, under most assumptions, alter cropping system choice. Alternatively, under a variety of assumptions, the imposition of an erosion tax shuts down cropping.

Since 2008, the euro area unemployment rate has increased constantly, while this economy's GDP was the same at the end of 2012 as it was in 2008. The recent trend of aggregate economic activity in this area illustrates the risk that an economy leaves its stability corridor, in which it usually progresses in a cyclical way, to enter an area of turbulence. In this area, the automatic stabilizers have weak feedback forces. To examine this kind of situation in a theoretical framework, this paper presents a model that relies both on Leijonhufvud's corridor and on Harrod's instability principle. This model allows a threshold to be defined beyond which the economy runs the risk of entering a cumulative process of simultaneous declines in growth and employment. However, the existence of such a process requires unemployment to have a sufficiently direct effect on the growth in aggregate demand, as seems to be the case nowadays.

Nicholas Georgescu-Roegen est connu à la fois pour sa contribution essentielle à lanalyse économique traditionnelle et pour sa volonté de fonder une approche bioéconomique. En nous appuyant sur la Méthodologie des Programmes de Recherche Scientifique de Lakatos et sur la réconciliation quil propose entre « histoire interne » et « histoire externe » des sciences, nous tentons de réévaluer la tentative de Nicholas Georgescu-Roegen de fonder un nouveau programme de recherche. Nous concluons en montrant léchec de cette tentative.