Stochastic evolution equations in Banach spaces and applications to the Heath–Jarrow–Morton–Musiela equations

The aim of this paper is threefold. Firstly, we study stochastic evolution equations (with the linear part of the drift being a generator of a \(C_{0}\)-semigroup) driven by an infinite-dimensional cylindrical Wiener process. In particular, we prove, under some sufficient conditions on the coefficients, the existence and uniqueness of solutions for these stochastic evolution equations in a class of Banach spaces satisfying the so-called \(H\)-condition. Moreover, we analyse the Markov property of the solutions.Secondly, we apply the abstract results obtained in the first part to prove the existence and uniqueness of solutions to the Heath–Jarrow–Morton–Musiela (HJMM) equations in weighted Lebesgue and Sobolev spaces.Finally, we study the ergodic properties of the solutions to the HJMM equations. In particular, we find a sufficient condition for the existence and uniqueness of invariant measures for the Markov semigroup associated to the HJMM equations (when the coefficients are time-independent) in the weighted Lebesgue spaces.Our paper is a modest contribution to the theory of financial models in which the short rate can be undefined.     

Optimal research and development and the cost of business cycles

While research and development (R&D) investment has been procyclical in the post-war period, recent literature suggests that the optimal path for R&D is countercyclical, and that the economy would be better off by subsidizing R&D in recessions. The objective of this paper is to analyze the welfare effects of distortions in the intertemporal allocation of R&D resources and to compare diverse policy interventions so as to improve social welfare. To this end, we introduce a calibrated dynamic stochastic general equilibrium model with Schumpeterian endogenous growth that is capable of explaining the observed procyclicality of R&D. Our results show that the cost of business cycles is lower in the decentralized economy with procyclical R&D than in the efficient allocation with countercyclical R&D. This is because the suboptimal propagation of shocks in the decentralized equilibrium offsets some of the existing steady-state distortions. In this second-best context, countercyclical R&D subsidies have no positive effect on welfare. In contrast, fiscal policies aimed at restoring the optimal steady-state produce large welfare gains.     

“A profit table or a profit calculator?” A note on the design of Cournot oligopoly experiments

We report on an experiment conducted to evaluate the effects of varying the way in which market information is presented to participants in laboratory Cournot duopolies. We find that the most standard variations, which are the use of a profit table or a profit calculator, yield indistinguishable performance. However, the addition of a best-response option to the profit calculator tends to increase aggregate output to the Cournot level and decrease the incidence of tacit collusion.     

Behaviours and entrepreneurial intention: Empirical findings about secondary students

This paper aims to identify some factors that may be explaining differences among secondary students in start-up intentions. For that, the study develops an entrepreneurial intention model sustained by the use of Azjen’s Theory of Planned Behaviour (TBP). Using a sample of students aged between 14 and 15 years old, a questionnaire based on the Li?án and Chen’s Entrepreneurial Intention Questionnaire was administrated. The purpose is to test a model of entrepreneurial intention using structural equations. The findings point that TPB is an appropriate tool to model the development of entrepreneurial intention through pedagogical processes and learning contexts. The education and training should centre itself much more in changing personal attitudes than in knowledge. Moreover, it is desirable that an entrepreneurship educational programme could contribute to the development of competences related to entrepreneurship, social and civic skills, and cultural awareness.     

Continuous-time mean-variance portfolio optimization in a jump-diffusion market

In this paper, we take up an approach of (Lindberg, in Bernoulli, 15(2):464–474, 2009) who introduced a new parameterization of the Black–Scholes model that allows for an easy solution of the continuous-time Markowitz mean-variance problem. We generalize the results of (Lindberg, in Bernoulli, 15(2):464–474, 2009) to a jump-diffusion market setting and slightly correct the proof and the assertion of the main result. Further, we demonstrate the implications of the Lindberg parameterization for the stock price drift vector in different market settings, analyse the dependence of the optimal portfolio from jump and diffusion risk and finally indicate how to use the method. We particularly also show how the optimal strategy can be obtained with the restricted use of historical data.     

Optimal macroeconomic policies in a financial and economic crisis: a case study for Slovenia

In this paper, we study different and, in particular, “optimal” reactions of fiscal (and to some extent monetary) policies to the financial and economic crisis of 2007–2009 in Slovenia, a small open economy that is part of the Economic and Monetary Union (EMU). Using an econometric model of the Slovenian economy, we simulate the effects of the global crisis under the assumption of no-policy reactions, i.e. assuming that macroeconomic policies are conducted without attempting to deal with the effects of the crisis. Next, we study the possibilities of fiscal policy reducing or even annihilating the effects of the crisis. We also investigate the optimal reaction of fiscal policies based on the assumption that Slovenian policy-makers behave as though they were optimizing an objective function. We show that optimal policies call for only a very modestly active countercyclical role of fiscal policies. There are strong trade-offs between countercyclical fiscal policies and the requirements of fiscal solvency.     

Income distribution, efficiency and rationing

This paper studies the impacts of income distribution on the efficiency of trade mechanism and rationing of agents who are priced out of trade in a dynamic search model with two-sided asymmetric information. Buyers and sellers have asymmetric information about valuations and incomes respectively. In such a frictional environment, the effects of several variants of changes in income distribution on efficiency of trading mechanism and the population of rationed buyers and sellers are elaborated.     

PAALiativ: Technik als Chance?

Assistenztechnologie im Wohnumfeld — Die Terminalphase des Lebens in h?uslicher Umgebung verbringen zu k?nnen entspricht dem Wunsch der meisten Menschen. In Oldenburg startete mit PAALiativ ein Projekt, mit dem exemplarisch nach M?glichkeiten der technischen Unterstützung für ein selbstbestimmtes Leben Schwerstkranker gesucht wird.     

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