Differential Evolution: A Tool for Global Optimization

This report describes a tool for global optimization that implements the Differential Evolution optimization algorithm as a new Excel add-in. The tool takes a step beyond Excel’s Solver add-in, because Solver often returns a local minimum, that is, a minimum that is less than or equal to nearby points, while Differential Evolution solves for the global minimum, which includes all feasible points. Despite complex underlying mathematics, the tool is relatively easy to use, and can be applied to practical optimization problems, such as establishing pricing and awards in a hotel loyalty program. The report demonstrates an example of how to develop an optimum approach to that problem.

Service Loyalty: An Integrative Model and Examination across Service Contexts

Marketing academics and practitioners generally agree that customer loyalty is vital to business success. There is less agreement on the factors that determine customer loyalty, particularly in service contexts. Research on the determinants of service loyalty has taken three distinct paths: 1) quality/value/satisfaction; 2) relationship quality; and, 3) relational benefits. In this research, the authors coalesce these paths to derive a model that links dimensions of customer loyalty (cognitive, affective, intention, and behavioral) with a system of determinants. The model is tested with data from varied services (airlines, banks, beauty salons, hospitals, hotels, and mobile telephone) and 3,500 customers in China. Results are consistent across contexts and support a multidimensional view of customer loyalty. Key loyalty determinants are customer satisfaction, commitment, service fairness, service quality, trust, and a construct new to service loyalty models—commercial friendship. The research contributes to the literature by providing a more complete, integrated view of customer loyalty and its determinants in services contexts.