Land subsidence threatens the living conditions of roughly 1.2 billion people worldwide in deltaic regions characterized by soft top soil. Economic activity in deltaic regions requires lowering the groundwater levels to keep the land sufficiently dry to maintain productivity, which, however,...

We develop a flexible single-state model to represent tradeoffs between infections and activity during the early phase of an epidemic. We prove that optimal policy is continuous in the state but discontinuous in the deterministic arrival date of a cure; optimal lockdowns are followed by stimulus...

The combinatorial integral approximation (CIA) decomposition suggests solving mixed-integer optimal control problems by solving one continuous nonlinear control problem and one mixed-integer linear program (MILP). Unrealistic frequent switching can be avoided by adding a constraint on the total...

In this paper we apply an augmented Lagrange method to a class of semilinear elliptic optimal control problems with pointwise state constraints. We show strong convergence of subsequences of the primal variables to a local solution of the original problem as well as weak convergence of the...

We examine within a life-cycle set-up the simultaneous choice of health care and retirement (together with consumption), when health care contributes to both a reduction in mortality and in morbidity. Health tends to impact on retirement via morbidity, determining the disutility of work, and...

This paper presents an optimal control model to analyze reforestations with two different species, including commercial values, carbon sequestration and biodiversity or scenic values. We solve the model qualitatively with general functions and discuss the implications of partial or total...

This paper derives and estimates rules for fiscal policy that prescribe the optimal response to changes in unemployment and debt. We combine the reduced-form model of the economy from a linear VAR with a non-linear welfare function and obtain analytic solutions for optimal policy. The variables...

In this paper we prove a deterministic approximation theorem for a sequence of Markov decision processeswith finitely many actions and general state spaces as they appear frequently in economics, game theory and operations research. Using viscosity solution methods no a-priori differentiabililty...

We present a set of necessary and sufficient conditions for a class of optimal control problems with pure state constraints for which the objective function is linear in the state variable but the objective function is only required to be upper semi-continuous in the control variable. We apply...

We study how preference heterogeneity affects travel behavior and congestion pricing in a dynamic flow congestion model. We formulate and solve a multi-point optimal control problem using a Hamiltonian-based method to derive the social optimum. The properties of the travel equilibrium are...