This statistical exercise attempts to quantify the economic contribution of rail to the Scottish economy. Part of this involves coming up with theoretical scenarios of partial reduction in, or total removal of rail provision. The authors clearly explain that there are too many variables in play to produce accurate figures from this but do conclude that "the railway in Scotland provides significant benefits to users and non-users in excess of the subsidy to the rail sector."
In a section headed "Wider economic impacts" Oxera states that these "arise when there is a change in the transport network, and accrue to people and businesses beyond the users and providers of the network. These effects enable higher long-term economic output and growth, and can be interpreted as the medium- to long-term spillover benefits of the rail sector to other industries, and to the overall performance of the economy."
"We estimate a range of wider economic impacts of the rail sector using established transport economics techniques. These benefits take the form of increased clustering of businesses, reduced congestion on the road network and increased output. Oxera estimates that these are worth between £64m and £652m to the Scottish economy."