This book constitutes the refereed proceedings of the 12th International Conference on Economics of Grids, Clouds, Systems, and Services, GECON 2015, held in Cluj-Napoca, Romania, in September 2015.

The 11 revised full papers and 10 paper-in-progress presented were carefully reviewed and selected from 38 submissions. The presentation sessions that have been set up are: resource allocation, service selection in clouds, energy conservation and smart grids, applications: tools and protocols, community networks and legal and socio-economic aspects.

This book constitutes revised selected papers from the 15th International Conference on Informatics in Economy, IE 2016, held in Cluj-Napoca, Romania, in June 2016. The 10 full papers and 4 short papers presented in this volume were carefully reviewed and selected from 31 extended paper submissions for this book.