**Author details**

Giovanna Testa Department of Management Studies and Quantitative Methods, University of Naples "Parthenope", Naples, Italy

\*Address all correspondence to: giovanna.testa@uniparthenope.it

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
