Results 1  10
of
17
The economics of nonconvex ecosystems
 Introduction.” Environmental and Resource Economics
, 2003
"... ..."
Skiba points for small discount rates
 Journal of Optimization Theory and Applications
, 2006
"... The present article uses perturbation techniques to approximate the value function of a economic minimisation problem for small values of the discount rate. This can be used to obtain the approximate location of Skiba states (or indifference thresholds) in the problem; these are states for which the ..."
Abstract

Cited by 3 (0 self)
 Add to MetaCart
(Show Context)
The present article uses perturbation techniques to approximate the value function of a economic minimisation problem for small values of the discount rate. This can be used to obtain the approximate location of Skiba states (or indifference thresholds) in the problem; these are states for which there are two distinct optimal state trajectories, converging to different optimal steady states. It is shown that the sets of indifference thresholds are locally smooth manifolds. For a simple example, all relevant quantities are computed explicitely. Moreover, the approximation can be used to obtain parameterdependent approximations to indifference manifolds.
Organising Centres in the Semiglobal Analysis of Dynamical Systems
"... The notion of organising centre of a bifurcation diagram is used as an ordering principle in the analysis of nonlinear problems in pure and applied dynamical systems theory. When considering a given, generic nparameter family of dynamical systems the codimension n bifurcations are isolated in the p ..."
Abstract

Cited by 3 (0 self)
 Add to MetaCart
(Show Context)
The notion of organising centre of a bifurcation diagram is used as an ordering principle in the analysis of nonlinear problems in pure and applied dynamical systems theory. When considering a given, generic nparameter family of dynamical systems the codimension n bifurcations are isolated in the parameter space, generating a more global array of lower codimension bifurcations. It often makes sense to add one extra parameter to the system, e.g., by varying a ‘constant ’ coefficient. In such cases, semiglobal parts of the given ndimensional bifurcation set can be understood as generic slices in versal unfoldings of codimension n +1singularities. This can give great insight in the structure of the given system, as we shall illustrate in two extensive case studies.
Optimal treatment of an SIS disease with two strains. Unpublished manuscript, http://www.edgepage.net/papers2011/ SIS%20Two%20Strains%20%20Selma%20Telalagic.pdf, accessed 16
, 2011
"... This paper explores optimal treatment of an SIS (SusceptibleInfectedSusceptible) disease that has two strains with di¤erent infectivities. When we assume that neither eradication nor full infection are possible, it is shown that there are two categories of equilibria. First, there are two continua ..."
Abstract

Cited by 1 (0 self)
 Add to MetaCart
This paper explores optimal treatment of an SIS (SusceptibleInfectedSusceptible) disease that has two strains with di¤erent infectivities. When we assume that neither eradication nor full infection are possible, it is shown that there are two categories of equilibria. First, there are two continua of interior equilibria characterised by a
xed, positive total level of infection, where both strands of the disease prevail. It is hypothesised that a Skiba curve of indi¤erence lies between them. Second, there are two sets of equilibria where one strand of the disease is eradicated asymptotically. The feasibility of equilibria depends on parameter assumptions; a combination of low natural rate of recovery and large di¤erence between infectivities leaves only a small proportion of equilibria as feasible. Simulations exploring the relationship between cost and optimal policy are carried out. There exists a parameter range such that, counterintuitively, it is optimal to allow the highinfectivity strain of the disease to prevail, while asymptotically eradicating the lowinfectivity strain. Within this parameter range, there is added bene
t from policy exibility. At higher costs, simulations of the interior equilibria demonstrate the existence of a Skiba curve. The curve delineates two regions, each of which has a clear optimal policy.
From Mind to Market: A Global, Dynamic Analysis of R&D
, 2013
"... Tinbergen Institute has two locations: ..."
(Show Context)
The Optimal Control of Infectious Diseases via Prevention and Treatment
"... This paper fully characterizes the optimal control of a recurrent infectious disease through the use of (nonvaccine) prevention and treatment. The dynamic system may admit multiple steady states and the optimal policy may be path dependent. We find that an optimal path cannot end at a point with m ..."
Abstract

Cited by 1 (0 self)
 Add to MetaCart
This paper fully characterizes the optimal control of a recurrent infectious disease through the use of (nonvaccine) prevention and treatment. The dynamic system may admit multiple steady states and the optimal policy may be path dependent. We find that an optimal path cannot end at a point with maximal prevention; it is necessarily zero or at an intermediate level. In contrast, an optimal path must end at a point at which treatment is either maximal or minimal. We show that treatment and prevention are imperfect substitutes and may or may not be used in conjunction, depending on the state of the system. This means that optimal paths do not generally approach steady states as rapidly as possible. We show that for some parameterizations, it is always optimal to go to a specific steady state (either a high or a low prevalence one) while for others, the optimal path and steady state depend on initial conditions and thus there is hysteresis. We find that the comparative statics with respect to the rates of infectivity and recovery may radically differ across steady states, which has important policy implications. Last, we illustrate the main conclusions of the formal analysis by simulations.
Selective harvesting Evolution
, 2006
"... This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal noncommercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or sel ..."
Abstract
 Add to MetaCart
(Show Context)
This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal noncommercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier’s archiving and manuscript policies are encouraged to visit:
and
, 2005
"... Many economic problems can be formulated as dynamic games in which strategically interacting agents choose actions that determine the current and future levels of a single capital stock. We study necessary conditions that allow us to characterize Markov perfect Nash equilibria (MPNE) for these games ..."
Abstract
 Add to MetaCart
(Show Context)
Many economic problems can be formulated as dynamic games in which strategically interacting agents choose actions that determine the current and future levels of a single capital stock. We study necessary conditions that allow us to characterize Markov perfect Nash equilibria (MPNE) for these games. These conditions result in an auxiliary system of ordinary differential equations that helps us to explore stability, continuity and differentiability of MPNE. The techniques are used to derive detailed properties of MPNE for several games including the exploitation of a finite resource, the voluntary investment in a public capital stock, and the intertemporal consumption of a reproductive asset. JEL classification: C73; D92; Q22
Managing the environment and the economy in the presence of hysteresis
, 2008
"... and irreversibility ..."
(Show Context)
In Defense of Trusts: R&D Cooperation in Global Perspective∗
, 2012
"... We reexamine the tradeoff between the benefits of allowing firms to cooperate in R&D and the increased potential for product market collusion that R&D cooperatives bring about. For that we utilize a dynamic model of R&D whereby we do not restrict ourselves to a local analysis. That is, ..."
Abstract
 Add to MetaCart
We reexamine the tradeoff between the benefits of allowing firms to cooperate in R&D and the increased potential for product market collusion that R&D cooperatives bring about. For that we utilize a dynamic model of R&D whereby we do not restrict ourselves to a local analysis. That is, initial marginal costs may exceed the choke price such that R&D efforts can take place prior to production. Our framework yields four distinct scenarios, which includes the situation where firms continue to invest in developing further existing technologies although these technologies are destined to leave the market. We show that an extension of the cooperative agreement towards collusion in the product market is not necessarily welfare reducing: the full cartel develops further a wider range of initial technologies, it invests more in R&D such that process innovations are pursued more quickly, and it maintains a wider range of technologies.