By using an I-O table, several indicators can be calculated, namely the output
multiplier, income multiplier, backward linkage and forward linkage. These indica-
tors provide valuable information on the importance of the ICT sector in the economy.
A basic issue that we need to address here is the definition of the ICT sector/product.
Since 1998, the OECD has been developing an ICT sector/product definition and it has
been revised twice. The first ICT definition was based on ISIC Rev. 3 in 1998 and it was
followed by the revised ICT sector definition based on ISIC Rev. 3.1 in 2002. The last
version is the second ICT sector definition based on ISIC Rev. 4. The resultant detailed
definition is presented in Fig. 1. Before we conduct the analysis, we need to define the
scope of the sector. If we use the latest I-O Table which follows ISIC Rev. 4 definition,
then we should use the second ICT sector definition by OECD (2007). Table 1 shows the
detailed ICT sector definition based on 4 digits ISIC Rev. 4 definition.