In this paper we consider the single-machine setup times scheduling with general effects of deterioration and learning. By the general effects of deterioration and learning, we mean that the actual job processing time is a general function of the processing times of the jobs already processed and its scheduled position. The setup times are proportional to the length of the already processed job...

The aim of this paper is to discuss the problem of modelling and optimising condition-based maintenance policies for a deteriorating system in presence of covariates. The deterioration is modelled by a non-monotone stochastic process. The covariates process is assumed to be a time-homogenous Markov chain with finite state space. A model similar to the proportional hazards model is used to show ...

Does Mental Productivity Decline with Age? Evidence from Chess Players We use data on international chess tournaments to study the relationship between age and mental productivity in a brain-intensive profession. We show that less talented players tend to leave the game in the earliest phases of their career. When the effects of age on productivity vary with unobserved ability, commonly used fi...