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...

This paper considers a class of optimal control problems that allows jumps in the state variable. We present the necessary optimality conditions of the Impulse Control Maximum Principle based on the current value formulation. By reviewing the existing impulse control models in the literature, we...

In this paper we describe three different algorithms, from which two (as far as we know) are new in the literature. We take both the size of the jump as the jump times as decision variables. The first (new) algorithm considers an Impulse Control problem as a (multipoint) Boundary Value Problem...

This paper considers a firm that has the option to undertake product innovations. For each product innovation the firm has to install a new production plant. We find that investments are larger and occur in a later stadium when more of the old capital stock needs to be scrapped. Moreover, we...

In this article we analyze how the presence of thresholds influences multi agent decision making situations. We introduce a class of discounted autonomous optimal control problems with threshold effects and discuss tools to analyze these problems. Later, using these results we investigate two...

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...

We use Norwegian micro-data to identify the driving forces behind unemployment spells following temporary- and permanent dismissals. The duration of unemployment spells for permanently dismissed workers is primarily explained by individual resources and economic incentives, while spell-duration...