The economic importance of the port system
In many empirical studies, the estimate of indirect employment is presented but it is not clearly explained how it is obtained. Generally, there is a reference to a multiplier, quoted from the literature, which transforms the direct employment estimate into an estimate of indirect employment. Consequently, such multiplier is somewhat ‘ad hoc’, external to the analytical framework used.
In other applications, the indirect employment is said to be derived from inputs bought by the port sector from other sectors. Employmentoutput ratios, derived from the national I-O tables, are then used to come up with an estimate of indirect employment. In such a case, the entire backwardforward linkage structure is lost. Coppens (2005) is, to our knowledge, the only paper that tries to define in a sound approach what is meant by ‘indirect effect’. He defines it on the basis of the I-O model, but fails to account for some recent theoretical developments.
In this section we present and apply a methodology that provides a coherent and explicit framework to estimate the total output and employment importance of a port.
The analysis presented in the first subsection is useful since it provides an estimate of the level of integration of the port system within the economy. However, this is only a starting point because it does not consider the absolute