High-speed systems and external rate of return appraisal: the case of Swissmetro and the Basel-Zurich connection, milestones for a blueprint

The notion of external rate of return belongs to economics still to come, or rather said, socioeconomics as it mingles knowledge and observable reality seen through several disciplinary approaches. It clearly stems from the more established concept of “Internal rate of return” and suggests, by homology, some similar processing and relations between an objective and expected forms of return through time, yet at the same time, some basic difference as the term “external” precisely stresses. External, in most cases indicates that an identifiable influence or even a benefit of some form (it can be the contrary too: a negative aspect to avoid), takes place outside of the envisaged market relationship. We would like to emphasise, in the case of a major infrastructure development such as a high-speed system, how the external rate of return can complement the internal rate of return, what it is made of, and above all, what decisive role it can play in public decision-making and stakeholders’ governance.