Some unfamiliar dynamics of a familiar macro model a note

The idea that for small disturbances the full employment equilibrium is stable while for large disturbances it is unstable was coined by Leijonhufvud in the notion of a corridor. We discuss the existence of a corridor in the standard Keynesian-monetarist textbook macro-model. It turns out that though the full employment steady state of this model may be locally stable — which is the case when the well-known Cagan condition holds — the model is never globally stable. This is due to the inherent non-linearity in the demand for money function, arising from non-negativity of the nominal rate of interest. Thus, perhaps surprisingly, the Cagan condition is both necessary and sufficient for the existence of a corridor in the Keynesian-monetarist model.This note is adapted from a paper presented at the European Meeting of the Econometric Society, Bologna, August 1988. I would like to thank Søren Bo Nielsen and Peter Birch Sørensen (Copenhagen Business School), Thomas Lux (University of Bamberg), and two anonymous referees for helpful comments and suggestions. Remaining errors and shortcomings are mine.     

Two-moment decision models and rank-dependent utility

This paper extends results on the consistency of two-moment decision models with expected utility to rank-dependent utility preferences. The representations of expected utility and rank-dependent utility by --preferences have very similar comparative statics properties for linear distribution classes, except for the behavior with respect to small independent risks.I thank Soo Hong Chew for helpful discussion and three anonymous referees for valuable comments.     

Sector-specific capital, “Bang-bang” investment,and the Filippov solution

Bang-bang investment in a two-sector growth model with immobile capital is rational and leads to a unique and globally stable long-run equilibrium along a sliding trajectory. This steady state coincides with the stationary equilibrium in the traditional model with non-sector-specific capital.This article was written while the authors were visiting scholars at Cornell University. We gratefully acknowledge financial assistance from the Erasmus University Trust Fund and the Netherlands Scientific Organization. We would like to thank, without implicating, two anonymous referees, Martijn Herrmann, Jean-Marie Viaene, Claus Weddepohl, and the participants of seminars at the University of Maryland, the University of Montreal, and Erasmus University Rotterdam for perceptive remarks and useful comments. Jeroen Hinloopen and Rien Wagenvoort provided able graphical assistance. The views expressed in this article are those of the authors and not necessarily those of the World Bank.     

Price leadership in a duopoly with capacity constraints and product differentiation

This paper analyzes Stackelberg price leadership in a duopoly in which firms are capacity constrained and products are imperfect substitutes. Assuming symmetric substitutes, linear demand, and efficient rationing, we characterize the equilibria with an exogenously specified leader. Using the equilibrium profits derived from these games, we argue that over certain ranges of asymmetric capacities an endogenous price leader will emerge. When endogenous leadership does arise, it is the large capacity firm which is the leader. We thus provide a game theoretic model of dominant firm price leadership.Dave Furth's research has been undertaken as a part of the project Competition and Cooperation. Dan Kovenock has benefited from financial support from Erasmus University Rotterdam, the Krannert School of Management, and the Jay N. Ross Young Faculty Research Fellowship. We are grateful to Tom Faith for valuable research assistance. We have benefited from the comments of the editor, two anonymous referees, and participants at the European meetings of the Econometric Society in September 1989 and the North American Winter Meetings of the Econometric Society in December 1989.     

Versicherungsvertragliche Anzeigepflicht und Garantiehaftung für culpa in contrahendo

To sanction the insurant’s obligation to disclose the risk-relevant circumstances by the insurer’s exemption from performance does not comply with the ordinary pattern of pre-contractual liability. Instead of making the insurant responsible for the consequences of his breach of duty, the German Insurance Act subjects him to a guarantee which is comparable to the one imposed by the German Civil Code in the case of initial impossibility. The insurant has to guarantee that the facts which he did not, or at least not entirely, disclose do not cause any obligation of the insurer. The structure of this sanction is equivalent to the insurer’s so-called liability of performance. But contrary to the latter it can be justified by the specific importance of the insurant’s pre-contractual obligation of disclosure.     

Traumberuf oder Verlegenheitslösung?

So far relatively little is known about the situation of Ph.D. students in media and communication research. The main purpose of this study is, therefore, to shed light on the employment and working conditions for young scholars on their way to their doctoral degrees. We conducted a survey of 281 Ph.D. students in Germany, Switzerland and Austria. The results show that, on the one hand, young scholars are intrinsically highly motivated to do their jobs. On the other hand, they perceive an academic career as a very uncertain venture with many obstacles. Furthermore, several types of Ph.D. students can be distinguished: idealists, careerists and waverers. It is shown that only the idealists conform to the concept of a productive and interested scholar. The results are discussed in terms of their importance for the future development of the field.     

What Causes the Positive Price-Turnover Correlation in European Housing Markets?

This paper examines what determines the correlation between prices and turnover in European housing markets. Using a panel vector autoregressive model, we find that there is a particularly strong feedback mechanism between prices and turnover. Momentum effects are another important reason why prices and turnover are correlated. Common underlying factors, such as GDP and interest rates, also explain part of the price-turnover correlation. The results in this paper imply that, to understand price and turnover dynamics, it is important to model prices and turnover as two interdependent processes. There is a considerable bias in the coefficient estimates of standard house price models if this dependency is not explicitly taken into account.