n an infinite horizon optimal control problem, the Hamiltonian vanishes at the infinite horizon, when the differential equation is autonomous. The integrand in the integral criterion may contain the time explicitly, but it has to satisfy certain integrability conditions. A generalization of...

Piecewise deterministic control problems are problems involving stochastic disturbance of a special type. In certain situations, in an otherwise deterministic control system, it may happen that the state jumps at certain stochastic points of time. Examples are sudden oil finds, or sudden...

In this paper we present two general results on the existence of a discrete zero point of a function from the n-dimensional integer lattice Zn to the n-dimensional Euclidean space Rn. Under two different boundary conditions, we give a constructive proof using a combinatorial argument based on a...

In linear-quadratic control (LQC) problems with singular control cost matrix and/or singular transition matrix, we derive a reduction of the dimension of the Riccati matrix, simplifying iteration and solution. Employing a novel transformation, we show that, under a certain rank condition, the...

Dams are essential for water storage and hydropower generation, but change river flow patterns and endanger local environments. Dam projects may further exacerbate already existing problems in trans-boundary rivers. We consider three scenarios of institutional factors: (1) each country pursues...

Berger and Pope (2011) show that being slightly behind increases the likelihood of winning in professional and collegiate basketball. We extend their analysis to large samples of Australian football, American football and rugby matches, but find little to no evidence of such an effect for these...

We use Norwegian register data from 1989 to 2002 to estimate the causal effects of programme participation on the transition rate from unemployment to employment,by means of a dependent risks hazard rate model. The separate roles of causality and unobserved heterogeneity are non-parametrically...

Based on a combined register database for Norwegian and Swedish unemployment spells, we use the ‘between-countries-variation’ in the unemployment insurance systems to identify causal effects. The elasticity of the job hazard rate with respect to the benefit replacement ratio is around -1.0...

Building on register data describing monthly labour market status for the whole Norwegian population 1992-95, we estimate grouped competing risk hazard rate models for transitions between employment, unemployment and non-participation. The models impose no parametric restrictions on either...