Part 1. Introduction -- Chapter 1. Studying Digitalization Across Levels: An Overview and Introduction -- Part 2. Outsourcing and Multi-party Projects: Reflections and Experiences -- Chapter 2. The Early History of It Outsourcing – a Personal Reflection -- Chapter 3. How to Ensure Collective...

This paper presents two gravity models for the estimation of air passenger volume between city-pairs. The models include variables describing the general economic activity and geographical characteristics of city-pairs instead of variables describing air service characteristics. Thus, both...