This paper presents a profit-oriented shift scheduling approach for inbound contact centers. The focus is on systems in which multiple agent classes with different qualifications serve multiple customer classes with different needs. We assume that customers are impatient, abandon if they have to...

We show that specific nonlinear time series models such as SETAR, LSTAR, ESTAR and Markov switching which are common in econometric practice can hardly be distinguished from long memory by standard methods such as the GPH estimator for the memory parameter or linearity tests either general or...

Does it make us unhappier when we compare our current consumption with that of the Joneses or our own past achievements? This paper tries an answer without recurring on interpersonal utility comparisons. It calibrates an economy under three different assumptions, non-comparing utility, and...

Household poverty is a powerful motive for child labor and working frequently comes at the expense of schooling for children. Accounting for these natural links we investigate whether and when there is an additional role for community norms and how the social evaluation of schooling evolves over...

In non-linear regression models, such as the probit model, coefficients cannot be interpreted as marginal effects. The marginal effects are usually non-linear combinations of all regressors and regression coefficients of the model. This paper derives the marginal effects in a probit model with a...

This paper analyzes the Steiner-Weber-Problem with piecewise linear or piecewise constant transportation costs. These non-differentiable cost functions are analyzed using different one-step and dynamic linearization methods, which are based on approximations via average and marginal costs. An...

This paper presents a linear programming approach to analyze and optimize flow lines with limited buffer capacities and stochastic processing times. The basic idea is to solve a huge but simple linear program that models an entire simulation run of a multi-stage production process in discrete...

This paper presents an optimization-based solution approach for the dynamic multi-level capacitated lot sizing problem (MLCLSP) with positive lead times. The key idea is to solve a series of mixed-integer programs in an iterative fix-and-optimize algorithm. Each of these programs is optimized...

This paper proposes a new unit root test against a non-linear exponential smooth transition autoregressive (ESTAR) model. The new test is build upon the non-standard testing approach of Abadir and Distaso (2007) who introduce a class of modified statistics for testing joint hypotheses when one...